I’ve currently disabled users from selecting the “Essential” forum theme as it seems to be locking up the page for people.
The current fix if you’re using Essential and the page freezes while loading - if you can access the forum on another device (hopefully not using the Essential theme) you can go to profile>preferences>interface and choose a new theme, then select the box to make it the theme on all your devices and make sure you hit “Save” at the bottom. Then reload the page on the device that’s locked up.
If you cannot do this or know someone having this problem, let us know (you can send an email to support@intfiction.org outside the forum) and we can switch you to the default theme to get you back in.