Most WordPress error messages give you an idea of what’s causing problems on your site. The “Warning: Cannot modify h
Posted: Thu Feb 13, 2025 4:39 am
Most WordPress error messages give you an idea of what’s causing problems on your site. The “Warning: Cannot modify header information – headers have already been sent by” error is no exception. If a PHP file can’t be executed due to a problem in its code, you’ll encounter this message.
There are several potential causes for the “Cannot modify header information” error. Fortunately, the message itself will tell you which file is causing the problem. It even points out the line of code that contains the problem.
In this article, we're going to talk about this error and it malaysia whatsapp number datas causes. Then, we'll go over two ways to fix the problem. Let's get started!
What Causes the Error “Cannot Modify Header Information: Headers have already been Sent By”
As we mentioned before, you'll encounter this error when one of your site's .php files fails to execute. WordPress relies on .php files , such as wp-config.php and functions.php , for its core functionality.
If there is a problem within one of the .php files that your website needs to load, you will see an error message similar to this:
Warning: Cannot modify header information - headers already sent by (output started at /home/public_html/wp-config.php:#) in /home/public_html/wp-includes/file-example.php on line 33
Fortunately, the “Cannot modify header information” error provides a lot of information that makes troubleshooting relatively easy. The message will tell you about two files: the first one contains the problem, which prevents the second one from running.
At the end of the error message, you'll see a section that says "line XX." This shows the location of the specific code that's causing the problem.
Usually, the problem in the PHP code is quite easy to fix. Some common causes that can trigger the error message are
There are several potential causes for the “Cannot modify header information” error. Fortunately, the message itself will tell you which file is causing the problem. It even points out the line of code that contains the problem.
In this article, we're going to talk about this error and it malaysia whatsapp number datas causes. Then, we'll go over two ways to fix the problem. Let's get started!
What Causes the Error “Cannot Modify Header Information: Headers have already been Sent By”
As we mentioned before, you'll encounter this error when one of your site's .php files fails to execute. WordPress relies on .php files , such as wp-config.php and functions.php , for its core functionality.
If there is a problem within one of the .php files that your website needs to load, you will see an error message similar to this:
Warning: Cannot modify header information - headers already sent by (output started at /home/public_html/wp-config.php:#) in /home/public_html/wp-includes/file-example.php on line 33
Fortunately, the “Cannot modify header information” error provides a lot of information that makes troubleshooting relatively easy. The message will tell you about two files: the first one contains the problem, which prevents the second one from running.
At the end of the error message, you'll see a section that says "line XX." This shows the location of the specific code that's causing the problem.
Usually, the problem in the PHP code is quite easy to fix. Some common causes that can trigger the error message are