Changed Theme- Can't Login

Any suggestions would be appreciated.

Try this:

Ops, sorry ??
This: https://powerdevelopmentinc.com/wordpress/wp-login.php

Use your ftp client to remove the theme that’s causing the issue, then go back to your site using the login url and try to log back in. That should force the default theme to reload. If you get a blank page, clear your browser cache, and try again.

Dhikra, the link you provided worked. Thanks very much. Problem solved.