Keep getting this error in different areas such as using the Network Admin area to Add Site, and also when trying to upload a new theme.
Clifford P answers:
Try enabling [[LINK href="http://codex.wordpress.org/WP_DEBUG"]]WP_DEBUG[[/LINK]] and see if there are helpful errors. Also, try disabling all plugins and using a reliable, unmodified theme like default Twenty Eleven to see if you still get the error/alert message.
This could be due to an out of date plugin, WordPress core or out of date themes.
I suggest updating WordPress and your plugins. if message stills comes up then try disabling plugins until the message goes away (start with google analytics) and you will find your culprit. Otherwise try adding an up to date theme to see if you get the same message.
Other things to test
1. Upload theme through FTP and remember to unzip it just upload the parent folder where the files reside.
2. Reuplod admin files
3. Check for proper Multisite htacess settings http://codex.wordpress.org/Multisite_Network_Administration#.htaccess_and_Mod_Rewrite
4. Custom post types : Limitation in lenght of post names (can also cause this error)
Francisco Javier Carazo Gil answers:
Maybe there is a problem with system resources. Well, try increasing your max_execution_time, your max_input_time, and your memory_limit, via the php.ini. If you do not have a php.ini file, use the PHP Config icon in the cPanel to install one. Also set your php mode to Single php.ini while you are there.
Maybe try something like:
max_execution_time = 120
max_input_time = 120
memory_limit = 64M
But also increase the
; Maximum size of POST data that PHP will accept.
post_max_size = 10M
; Maximum allowed size for uploaded files.
upload_max_filesize = 10M
If you are in your own server, you should do it directly into general php.ini if not, in the other one.
Tell the sysadmin if the problem continous to increase these parameters.
Abdelhadi Touil answers:
Try to deactivate all plugins and then test if the problem continue. If not then one of your plugins is the problem, so try to activate one by one until you find the affecting plugin.