So, anyone else got this?
Dai said he did, so I'm making this thread to see if once its created we can see the darn thing.
lulz…I think I just fixed it, maybe. Can anybody else get to this?
By the way, here's the fix:
When it gives you the "page does not exist (yet)" bit, click the "Create Page" link, find the relevant section in the help page above (in this case forum:thread was the problem), copy the module/do not touch text from the help page and paste into the content box of the page you're creating, rename the title to match what's listed on the fix page (in this case "Forum Thread") and save. Once it saves it will give you an "invalid thread" or "invalid page" message, but you should be able to go back and access forum threads without a problem.
This means someone tried to delete a thread instead of moving it to a hidden category made for holding "deleted" stuff, which is apparently the preferred method of getting rid of unwanted forum stuff. Deleting an individual post won't cause problems, but deleting anything above that in the hierarchy will screw things up. You can still delete things (so that they're gone forever and ever) instead of just moving them without doing permanent damage to the forum, but you'll have to recreate the forum:thread or forum:category or whatever relevant page every time after you're finished if you want it to work.
So I guess it's up to daijitsu and/or Dalndox to decide which one we're going to use, since I think you need admin access to use the hidden category method, but any mod can delete/recreate the pages. *shrugs*