WordPress and the Headers Already Sent Warning

The scenario begins like any other troubleshooting scenario. You’ve just installed a plugin or theme on your WordPress blog, modified a file, or you’re simply checking on your blog. Suddenly, an error message just like the following looms over the page you’re viewing like a dark cloud. Warning: Cannot modify header information – headers already sent by (output started at /path/blog/wp-config.php:34) in /path/blog/wp-login.php on line 42 Remember the first rule in troubleshooting, don’t panic! First, you need to interpret the error message. Offhand, it would seem as if line 42 of the wp-login.php file was the source of the problem, but that’s a common misconception. In fact, the problem is on line 34 of the wp-config.php file, and line 42 of the wp-login.php file is just the victim. Now that you know where to look, what do you look for? Believe it or not, this problem is usually caused by […]