log in page not working

So the log in page for the membership site isn’t working properly.

http://www.wendypatton.com/subscriptions-and-training

Even when the correct log in and password info is entered, the page simply refreshes to the blank log in form. If an incorrect email or password is entered – it will update to say “incorrect password” – but a correct log in does not forward the membership page.

Ideas?

P.S. – This site was custom made by a former employee years ago, so there isn’t any available updates for this theme.