wp-login.php could not be found

I get this error anytime I try to log in to WP:

Not Acceptable

An appropriate representation of the requested resource /wp-login.php could not be found on this server.

Additionally, a 406 Not Acceptable error was encountered while trying to use an ErrorDocument to handle the request.

I guess my question is, where'd it go and how do I put it back?

I am able to get to the login screen just fine. That is the error I get regardless of the username and password that I enter.