Today I have changed my password and noticed that I could no longer access any of the ShareCG pages - they all show as a white blank page. I could still see the site through other computers, but Firefox would only give me a blank page, no error messages.
After trying different things, I figured it can be "fixed" by deleting the ShareCG cookies from Firefox. Now I can access the site again, and this might help other people if they get blank pages after changing their password.