A few days ago out of the blue, we encountered a problem with our Wordpress site. The front end runs fine, but when we went to sign in at wp-admin, it just came up with a blank page. We were able to get into the backend by using wp-login.php, but if we updated a page or post, it would come up with a blank page, but it would still update.
We've tried deactivating the plugins, switching themes, removing blank lines at the end of functions.php and wp-config.php, backing up, deleting, and then re-uploading the wp-admin file, etc. We turned on error reporting, but it didn't come up with anything.
I think it could be a problem with the auth redirects since we can still get in to the wp-admin once we are logged in and the pages aren't redirecting correctly after they are saved. I also set up the wp-admin index page to print out some test lines to see if I could find how far the code was getting before breaking and it seemed to have problems right around the auth_redirect line.
We're just wondering if anyone else has had this problem and what they did to fix it.