WampServer

Well, I installed php_apc.dll onto my local server and everything has been working great, however when I try to access phpMyAdmin I get the following error:

Fatal error: Class 'PMA_Error_Handler' not found in C:\wamp\apps\phpmyadmin3.1.3\libraries\common.inc.php on line 57

I took a look at the file common.inc.php and followed all of the includes and even saw the class in the files that it is stating is not found.

Maybe a problem with globals?

Please help, this is horrible and google found nothing on this.

Sorry for bumping up this topic, but I encountered this error myself and it took me the whole day to solve. Generally what the problem is that the auto-cache feature seems now always to provide the expected results, as in this case a class definition is lost due to caching.

The solution is simply to add this line to php.ini and restart the apache server:
apc.cache_by_default = 0

If you want to have cache_by_default on, but also need access to PhpMyAdmin, you might want to check the apc.filters option that allows you to exclude files from being cached, using a regular expression.

More info on configuring APC can be found here:
[php.net]

Hope this helps!

Best regards,
doqunbop