i Upgraded my php to version 5.3.17 on my server 2 days ago and since then I get Fatal error: Out of memory when going to my wordpress admin.
All of my non wordpress sites are not affected.
So far i have:
added the line define('WP_MEMORY_LIMIT', '256M'); to config.php
edited default_constants.php to increase WP memory limits.
got my hoast to scan all of my files for anything that would be preventing WP from using memory, they found nothing after an 18 hour scan.
increased memory limit in php.ini to 512mb.
My host has checked my php configuration and confirmed that all is set correctly and that memory limits on the server are set high enough, (512MB)
My host has spent the best part of 2 days trying to find a problem with my server and have found nothing.
I have the exact same problem on 7 sites with wordpress installations.
The reason I updated my servers PHP version was because while trying to update my wordpress sites to the latest version using the auto update in the admin i kept getting memory error.
I have now manually updated all the wordpress sites and have even installed a fresh new install which also has the same problem.
they have now referred me to wordpress to find a solution so here I am!