A site I'm running is having problems. With pretty permalinks enabled, after login I get an "archive not found page", as WP tries to load a page slug "wp-login-php". If I set default permalink structure, WP tries to load http://www.example.com/wp-login.php/ and fails.
As far as I can tell, this problem just appeared. I had problems before with couple of posts - trying to update the posts would cause a similar problem. However, that happened with just three or four posts, so I didn't mind. Now I mind as I can't even log in to the site.
- setting .htaccess to default
- re-uploading WordPress files
- disabling mod_sec in .htaccess
Since I don't think this has anything to do with what I've done - as far as I can tell, there are no plugin or theme changes involved (I'm not the sole admin, so I can't be 100% sure, but I'm 99% sure) - I'm guessing this might be caused by some change in server settings.
But what could it be? It would help a lot if I could ask the domain guys to ask the host to fix a particular problem - I can't talk with the host support myself. Any ideas?