Our site was infected with Malware, and the file was cleaned.
So, after MANY reinstalls of our site, it will work fine for a while. Then, a file mysteriously appears in the wp-includes/js folder. The name of the file is "main.is", and the blog admin isn't accessible. Then, when I delete the file in question, I get a never ending redirect loop, and the wp-admin is still inaccessible.
I have tried removing all themes and plugins to no avail.