Upgrade to WordPress 2.6

August 11, 2008 1:40 am HiddenVorlon Tech Problems

I lost several hours today upgrading from WordPress 2.5 to 2.6.  I followed all of the installation instructions to the letter, but kept getting the following error message:

Warning: Cannot modify header information - headers already sent by....

After installing the new files and then uploading the old wp-config.php file, I was beating my head into the wall. 

WordPress 2.6

Finally, after debugging through things, I found that the WP 2.5 wp-config file has an extra newline character (’\n’) at the end of the %> tag.  Completely undetectable, I lost hours trying to solve the problem.  It appears that 2.5 was either more forgiving or there was some extra code in 2.6 that caused a problem with the extra newline.

I’m just posting this just in case anyone else runs into trouble - check the end of the wp-config.php file for any extra newline characters.