WordPress 3.6, fatal errors when installing or updating plugins & themes


New Member
Hi all, I'm having a problem with the latest WP version.

Fresh installations of WordPress 3.6 throw fatal errors when trying to install/update any plugins & themes. WP 3.5.2 works perfectly fine, but if I update it to 3.6 the same errors occur.

Specifically, I'm getting the following error:

Fatal error: Call to undefined method Plugin_Upgrader::init() in /<path>/wp-admin/includes/class-wp-upgrader.php on line 394 / 421 / etc


Fatal error
: Call to undefined method Theme_Upgrader::init() in /<path>/wp-admin/includes/class-wp-upgrader.php on line 744

My VPS-3 runs Apache 2.4.6 with PHP 5.4.17 on suPHP mode (suEXEC is on).

I temporarily increased the php memory execution limit to 1024M to no avail.

Any ideas?
Thanks Dave,

Turns out the problem was not Apache's version or available ram. I had EAccelerator enabled in EasyApache and it somehow conflicted with suPHP. I disabled it, rebuilt apache 2.4 and now everything works fine :)
Last edited:
eAccelerator and suPHP don't play nice together because of file permissions.

Glad to hear you got everything resolved :)