I have the latest 3.5.1 WP installed. I have several plugins installed. Everything was working fine for about two weeks. I made no further changes. I noticed today I now get the error :
"500 - Internal server error.
There is a problem with the resource you are looking for, and it cannot be displayed."
Running IIS7 on Windows Server 2008.
PHP.ini has 128Mb allocated for memory (lots of threads suggest inc from 16Mb will often fix the error, but mine set to 128Mb anyway. I tried 256Mb just to see but no change).
I have tried accessing with IE9 with "friendly errors" disabled but I get the same error as with Firefox etc.
I tried listing all the files by modified date. All files have not changed for weeks except a couple in the cache folder of the Connections plugin. I deleted those cache files but the problem persists.
I have checked my php.log and there are some errors but they all the same realting to the missing table of the login lockdown plugin, but that has always been there even when the site was working, so I can't see it being that either.
I have checked the paths in my wp-config.php file, database credentials etc. I can access my database via PHPMyAdmin and all looks OK there too. Its a total mystery.
I have another WP 3.5.1 site hosted on the same server and that is fine.
Can anyone suggest anything? Why has my site suddenly stopped working and how can I see what the cause is?