We were changing our wordpress site to use pretty links, but discovered that it broke old links. We tried to revert our changes, but whenever we open up /wp-admin/options-permalink.php (and only that page) we get a 500.0 internal server error. We run IIS 7.5 on Windows 7.
HTTP Error 500.0 - Internal Server Error C:\Program Files (x86)\PHP\v5.4.36\php-cgi.exe - The FastCGI process exited unexpectedly Detailed Error Information Module FastCgiModule Notification ExecuteRequestHandler Handler php-5.4.36 Error Code 0x000000ff Requested URL http://gwswpp1svrus:80/wp-admin/options-permalink.php Physical Path E:\path\to\wp-admin\options-permalink.php Logon Method Anonymous Logon User Anonymous
When we run
C:\Program Files (x86)\PHP\v5.4.36\php-cgi.exe E:\path\to\wp-admin\options-permalink.php
we get a 302 response. We don't have a .htaccess file anywhere, nor is anything showing up in \wp-content\debug.log or our custom logging folder.
On our dev server we get the same issue, but only intermittently. Roughly every other page load will result in an equivalent 500 error. On both we've noticed rather substantial spikes in CPU load whenever the page is refreshed - up to 95%.
EDIT: We ended up experiencing the intermittent errors on prod as well, and managed to change the setting back, however we're still getting 500 errors on both dev and prod servers, with default permalinks.
Any help would be appreciated.