{"id":546,"date":"2020-11-12T16:32:03","date_gmt":"2020-11-12T16:32:03","guid":{"rendered":"https:\/\/ccbill.com\/kb\/?p=546"},"modified":"2023-03-07T11:56:37","modified_gmt":"2023-03-07T11:56:37","slug":"cannot-modify-header-information-headers-already-sent-by","status":"publish","type":"post","link":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by","title":{"rendered":"How to Fix \u201cCannot Modify Header Information\u201d In WordPress"},"content":{"rendered":"<p class=\"h3\">Introduction<\/p>\n\n\n<p>Interpreting error messages in WordPress can be a time-consuming process. Finding an adequate solution to the problem is equally as difficult.<\/p>\n\n\n\n<p>To keep your website running like clockwork, you need to prevent long periods of downtime.<\/p>\n\n\n\n<p><strong>Find out how to fix the \u201cCannot Modify Header Information\u201d error in WordPress <\/strong>and get your site up and running quickly.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"400\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\" alt=\"Introductory image to WordPress Cannot Modify Header Information error.\" class=\"wp-image-547\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress-300x150.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress-768x384.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">What Does \u201cCannot Modify Header Information \u2013 Headers Already Sent By\u201d Mean?<\/h2>\n\n\n\n<p>The \u201cCannot Modify Header Information \u2013 Headers Already Sent By\u201d error indicates that a <strong>.php<\/strong> file cannot execute because an output is being sent before calling an HTTP header. Headers always need to precede the output.<\/p>\n\n\n\n<p>The most common causes of the \"Cannot Modify Header Information\" error are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Whitespaces before the opening <strong>&lt;?php<\/strong> token.<\/li>\n\n\n\n<li>Whitespaces after the closing <strong>?&gt;<\/strong> tag (if one is present).<\/li>\n\n\n\n<li>An HTML block is in front of the header within the <strong>.php<\/strong> file.<\/li>\n\n\n\n<li>Statements that produce output, such as <strong>print<\/strong> or <strong>echo<\/strong>, are being called before the header.<\/li>\n\n\n\n<li>Issues with an installed plugin.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How to Fix Warning \u201cCannot Modify Header Information\u201d?<\/h2>\n\n\n\n<p>The warning message tells you which file or files you need to review to fix the issue.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"224\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cannot-modify-header-information-error-wordpress.png\" alt=\"Example of &quot;Cannot Modify Header Information&quot; error in WordPress.\" class=\"wp-image-550\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cannot-modify-header-information-error-wordpress.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cannot-modify-header-information-error-wordpress-300x84.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cannot-modify-header-information-error-wordpress-768x215.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>In this example, the warning message indicates that the <strong>plugable.php<\/strong> file cannot execute due to an issue within the <strong>wp-config.php <\/strong>file.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Warning: Cannot modify header information - headers already sent by (output started at \/home\/public_html\/example.com\/wp-config.php:33) in \/home\/public_html\/example.com\/wp-includes\/plugable.php on line 1063<\/code><\/pre>\n\n\n\n<p>You need to access and check the code within the <strong>wp-config.php<\/strong> file.<\/p>\n\n\n\n<p>The message also provides the path to the file <em>\/home\/public_html\/example.com\/wp-config.php<\/em>. The number <strong>33<\/strong> points out the exact line within the code causing the error. <\/p>\n\n\n\n<p>The file path and the code line number are an excellent starting point when troubleshooting.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Corrupted PHP File<\/h3>\n\n\n\n<p>Use <strong>cPanel<\/strong> or an <strong>FTP client<\/strong> to access the server the website is located on. It is recommended to back up files before editing them.<\/p>\n\n\n\n<p>The examples in this guide are presented using cPanel.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Edit the File<\/h4>\n\n\n\n<p>1. Locate the file by using the path from the warning message. You can also use the search bar at the top of the cPanel dashboard. <\/p>\n\n\n\n<p>2. Select the file and click <strong>Edit<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"401\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cpanel-edit-file-wordpress.png\" alt=\"How to edit WordPress files using cPanel.\" class=\"wp-image-554\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cpanel-edit-file-wordpress.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cpanel-edit-file-wordpress-300x150.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/cpanel-edit-file-wordpress-768x385.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>3. Find the code line number specified in the warning message. Use the <strong>Go To Line<\/strong> option to locate lines in lengthy files quickly. <\/p>\n\n\n\n<p>4. Remove any whitespaces preceding the opening <strong>&lt;?php<\/strong> token.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"366\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/edit-file-wordpress-modify-header-error.png\" alt=\"Locate the code line causing the error and remove all whitespaces.\" class=\"wp-image-553\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/edit-file-wordpress-modify-header-error.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/edit-file-wordpress-modify-header-error-300x137.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/edit-file-wordpress-modify-header-error-768x351.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>5. If the file contains a <strong>?&gt;<\/strong> closing tag, ensure that there are no whitespaces after the tag. <\/p>\n\n\n\n<p>6. Click the <strong>Save Changes<\/strong> tab once you remove all redundant whitespaces.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"347\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/remove-whitespaces-php-file-wordpress.png\" alt=\"Save changes to the PHP file in cPanel.\" class=\"wp-image-557\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/remove-whitespaces-php-file-wordpress.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/remove-whitespaces-php-file-wordpress-300x130.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/remove-whitespaces-php-file-wordpress-768x333.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>Once you reload your webpage, the error message should disappear.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Move the Header Statement<\/h4>\n\n\n\n<p>Raw HTML elements in a <strong>.php<\/strong> file are rendered as a direct output. If an HTML element is placed before a header call, it can cause the \u201c<em>Cannot Modify Header Information \u2013 Headers Already Sent By<\/em>\u201d error. <\/p>\n\n\n\n<p>To fix the error, place the HTML block after the header statement.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"800\" height=\"78\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/html-block-before-header-remove.png\" alt=\"An HTML element preventing a header statement call.\" class=\"wp-image-558\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/html-block-before-header-remove.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/html-block-before-header-remove-300x29.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/html-block-before-header-remove-768x75.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure><\/div>\n\n\n<p>Functions that produce output such as <em>vprintf, printf, echo, flush,<\/em> and <em>print<\/em> statements must follow HTTP header calls. <\/p>\n\n\n\n<p>Review the .php file specified in the error message and correct the code. Always position header calls before the output producing elements and functions.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Replace the File<\/h4>\n\n\n\n<p>If you cannot locate the corrupt file or you are hesitant to edit the code, you can replace the entire file instead.<\/p>\n\n\n\n<p>1. Download the latest <a href=\"https:\/\/ccbill.com\/kb\/check-wordpress-version\" target=\"_blank\" rel=\"noreferrer noopener\">WordPress version<\/a>.<\/p>\n\n\n\n<p>2. Use an FTP client or cPanel to upload the new version of the file to your server.<\/p>\n\n\n\n<p>3. Overwrite the existing corrupt file with the new version.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"435\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/overwrite-file-wordpress-corrupt-php.png\" alt=\"Overwrite a corrupt PHP file in WordPress.\" class=\"wp-image-559\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/overwrite-file-wordpress-corrupt-php.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/overwrite-file-wordpress-corrupt-php-300x163.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/overwrite-file-wordpress-corrupt-php-768x418.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>4. Reload the previously unavailable webpage. <\/p>\n\n\n\n<p>You can upload and replace entire WordPress folders if the warning displays issues in multiple files.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Find the Plugin that Causes the Error<\/h3>\n\n\n\n<p>A faulty plugin can cause the \u201cCannot Modify Header Information\u201d error.<\/p>\n\n\n\n<p>1. Access your WordPress dashboard.<\/p>\n\n\n\n<p>2. <strong>Deactivate<\/strong> and then <strong>Activate<\/strong> each plugin, in turn, to determine if one of them is causing the issue. <\/p>\n\n\n\n<p>3. Refresh the affected webpage after every change you make.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"101\" src=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/deactivate-faulty-plugin-wordpress.png\" alt=\"Where to deactivate plugins in WordPress.\" class=\"wp-image-561\" srcset=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/deactivate-faulty-plugin-wordpress.png 800w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/deactivate-faulty-plugin-wordpress-300x38.png 300w, https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/deactivate-faulty-plugin-wordpress-768x97.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>Focus on the recently installed or updated plugins. The error will reappear once you turn on the failing plugin. <\/p>\n\n\n\n<p>Gather as much data as you can during this process and inform the plugin developers of the issues you encountered.<\/p>\n\n\n<p class=\"h3\">Conclusion<\/p>\n\n\n<p>By following the instructions in this guide, you have successfully identified and resolved the \u201c<em>Cannot Modify Header Information<\/em>\u201d error. <\/p>\n\n\n\n<p>Warning messages that flag similar issues are not uncommon in <a href=\"https:\/\/ccbill.com\/kb\/category\/wordpress\" target=\"_blank\" rel=\"noreferrer noopener\">WordPress<\/a>. The presented solutions are applicable in most cases with related underlying causes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A step-by-step guide explains how to solve the \"Cannot Modify Header Information\" in WordPress.<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[14,15],"tags":[],"class_list":["post-546","post","type-post","status-publish","format-standard","hentry","category-web-development","category-wordpress"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.8 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB<\/title>\n<meta name=\"description\" content=\"Learn how to edit or replace corrupted PHP files in WordPress. Fix the &quot;Cannot Modify Header Information&quot; error in a few short minutes.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB\" \/>\n<meta property=\"og:description\" content=\"Learn how to edit or replace corrupted PHP files in WordPress. Fix the &quot;Cannot Modify Header Information&quot; error in a few short minutes.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\" \/>\n<meta property=\"og:site_name\" content=\"CCBill Knowledge Base\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/ccbillBIZ\/\" \/>\n<meta property=\"article:published_time\" content=\"2020-11-12T16:32:03+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-03-07T11:56:37+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\" \/>\n<meta name=\"author\" content=\"Vladimir Kaplarevic\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@CCBillBIZ\" \/>\n<meta name=\"twitter:site\" content=\"@CCBillBIZ\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Vladimir Kaplarevic\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#article\",\"isPartOf\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\"},\"author\":{\"name\":\"Vladimir Kaplarevic\",\"@id\":\"https:\/\/ccbill.com\/kb\/#\/schema\/person\/1f198b1218f6343a2682022ac4395644\"},\"headline\":\"How to Fix \u201cCannot Modify Header Information\u201d In WordPress\",\"datePublished\":\"2020-11-12T16:32:03+00:00\",\"dateModified\":\"2023-03-07T11:56:37+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\"},\"wordCount\":723,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/ccbill.com\/kb\/#organization\"},\"image\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage\"},\"thumbnailUrl\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\",\"articleSection\":[\"Web Development\",\"WordPress Tutorials\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\",\"url\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\",\"name\":\"How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB\",\"isPartOf\":{\"@id\":\"https:\/\/ccbill.com\/kb\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage\"},\"image\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage\"},\"thumbnailUrl\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\",\"datePublished\":\"2020-11-12T16:32:03+00:00\",\"dateModified\":\"2023-03-07T11:56:37+00:00\",\"description\":\"Learn how to edit or replace corrupted PHP files in WordPress. Fix the \\\"Cannot Modify Header Information\\\" error in a few short minutes.\",\"breadcrumb\":{\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage\",\"url\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\",\"contentUrl\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png\",\"width\":800,\"height\":400,\"caption\":\"Introductory image to Wordpress Cannot Modify Header Information error.\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"KB Home\",\"item\":\"https:\/\/ccbill.com\/kb\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"WordPress Tutorials\",\"item\":\"https:\/\/ccbill.com\/kb\/category\/wordpress\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"How to Fix \u201cCannot Modify Header Information\u201d In WordPress\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/ccbill.com\/kb\/#website\",\"url\":\"https:\/\/ccbill.com\/kb\/\",\"name\":\"CCBill Knowledge Base\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/ccbill.com\/kb\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/ccbill.com\/kb\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/ccbill.com\/kb\/#organization\",\"name\":\"CCBill\",\"url\":\"https:\/\/ccbill.com\/kb\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/ccbill.com\/kb\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/10\/ccbill-logo.png\",\"contentUrl\":\"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/10\/ccbill-logo.png\",\"width\":160,\"height\":70,\"caption\":\"CCBill\"},\"image\":{\"@id\":\"https:\/\/ccbill.com\/kb\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/ccbillBIZ\/\",\"https:\/\/x.com\/CCBillBIZ\",\"https:\/\/www.linkedin.com\/company\/ccbill\",\"https:\/\/www.youtube.com\/c\/CCBillBiz\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/ccbill.com\/kb\/#\/schema\/person\/1f198b1218f6343a2682022ac4395644\",\"name\":\"Vladimir Kaplarevic\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/ccbill.com\/kb\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/cc08885e8fec32585bae8a0f5a1aef92f8c8c4fc33692e74e0ec2e63633d2478?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/cc08885e8fec32585bae8a0f5a1aef92f8c8c4fc33692e74e0ec2e63633d2478?s=96&d=mm&r=g\",\"caption\":\"Vladimir Kaplarevic\"},\"description\":\"Vladimir is a resident Tech Writer at CCBill. He has more than 8 years of experience in implementing e-commerce and online payment solutions with various global IT services providers. His engaging writing style provides practical advice and aims to spark curiosity for innovative technologies.\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB","description":"Learn how to edit or replace corrupted PHP files in WordPress. Fix the \"Cannot Modify Header Information\" error in a few short minutes.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by","og_locale":"en_US","og_type":"article","og_title":"How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB","og_description":"Learn how to edit or replace corrupted PHP files in WordPress. Fix the \"Cannot Modify Header Information\" error in a few short minutes.","og_url":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by","og_site_name":"CCBill Knowledge Base","article_publisher":"https:\/\/www.facebook.com\/ccbillBIZ\/","article_published_time":"2020-11-12T16:32:03+00:00","article_modified_time":"2023-03-07T11:56:37+00:00","og_image":[{"url":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png","type":"","width":"","height":""}],"author":"Vladimir Kaplarevic","twitter_card":"summary_large_image","twitter_creator":"@CCBillBIZ","twitter_site":"@CCBillBIZ","twitter_misc":{"Written by":"Vladimir Kaplarevic","Est. reading time":"5 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#article","isPartOf":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by"},"author":{"name":"Vladimir Kaplarevic","@id":"https:\/\/ccbill.com\/kb\/#\/schema\/person\/1f198b1218f6343a2682022ac4395644"},"headline":"How to Fix \u201cCannot Modify Header Information\u201d In WordPress","datePublished":"2020-11-12T16:32:03+00:00","dateModified":"2023-03-07T11:56:37+00:00","mainEntityOfPage":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by"},"wordCount":723,"commentCount":0,"publisher":{"@id":"https:\/\/ccbill.com\/kb\/#organization"},"image":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage"},"thumbnailUrl":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png","articleSection":["Web Development","WordPress Tutorials"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#respond"]}]},{"@type":"WebPage","@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by","url":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by","name":"How to Fix \u201cCannot Modify Header Information\u201d In WP | CCBill KB","isPartOf":{"@id":"https:\/\/ccbill.com\/kb\/#website"},"primaryImageOfPage":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage"},"image":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage"},"thumbnailUrl":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png","datePublished":"2020-11-12T16:32:03+00:00","dateModified":"2023-03-07T11:56:37+00:00","description":"Learn how to edit or replace corrupted PHP files in WordPress. Fix the \"Cannot Modify Header Information\" error in a few short minutes.","breadcrumb":{"@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#primaryimage","url":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png","contentUrl":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/11\/fix-cannot-modify-header-information-wordpress.png","width":800,"height":400,"caption":"Introductory image to Wordpress Cannot Modify Header Information error."},{"@type":"BreadcrumbList","@id":"https:\/\/ccbill.com\/kb\/cannot-modify-header-information-headers-already-sent-by#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"KB Home","item":"https:\/\/ccbill.com\/kb\/"},{"@type":"ListItem","position":2,"name":"WordPress Tutorials","item":"https:\/\/ccbill.com\/kb\/category\/wordpress"},{"@type":"ListItem","position":3,"name":"How to Fix \u201cCannot Modify Header Information\u201d In WordPress"}]},{"@type":"WebSite","@id":"https:\/\/ccbill.com\/kb\/#website","url":"https:\/\/ccbill.com\/kb\/","name":"CCBill Knowledge Base","description":"","publisher":{"@id":"https:\/\/ccbill.com\/kb\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/ccbill.com\/kb\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/ccbill.com\/kb\/#organization","name":"CCBill","url":"https:\/\/ccbill.com\/kb\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/ccbill.com\/kb\/#\/schema\/logo\/image\/","url":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/10\/ccbill-logo.png","contentUrl":"https:\/\/ccbill.com\/kb\/wp-content\/uploads\/2020\/10\/ccbill-logo.png","width":160,"height":70,"caption":"CCBill"},"image":{"@id":"https:\/\/ccbill.com\/kb\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/ccbillBIZ\/","https:\/\/x.com\/CCBillBIZ","https:\/\/www.linkedin.com\/company\/ccbill","https:\/\/www.youtube.com\/c\/CCBillBiz"]},{"@type":"Person","@id":"https:\/\/ccbill.com\/kb\/#\/schema\/person\/1f198b1218f6343a2682022ac4395644","name":"Vladimir Kaplarevic","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/ccbill.com\/kb\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/cc08885e8fec32585bae8a0f5a1aef92f8c8c4fc33692e74e0ec2e63633d2478?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/cc08885e8fec32585bae8a0f5a1aef92f8c8c4fc33692e74e0ec2e63633d2478?s=96&d=mm&r=g","caption":"Vladimir Kaplarevic"},"description":"Vladimir is a resident Tech Writer at CCBill. He has more than 8 years of experience in implementing e-commerce and online payment solutions with various global IT services providers. His engaging writing style provides practical advice and aims to spark curiosity for innovative technologies."}]}},"_links":{"self":[{"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/posts\/546","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/comments?post=546"}],"version-history":[{"count":20,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/posts\/546\/revisions"}],"predecessor-version":[{"id":4881,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/posts\/546\/revisions\/4881"}],"wp:attachment":[{"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/media?parent=546"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/categories?post=546"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ccbill.com\/kb\/wp-json\/wp\/v2\/tags?post=546"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}