The I login to the site with user name and password and click on keep me logged in, the page comes up with the following message

Invalid Redirect URL (http://www.antique-locks.com/forum.php)

When I go to the page the next day I am no longer logged in and the same thing occurs.

Using an iMac OSX El Capitan 10.11.6 with Safari 9.1.2.

Any suggestions?