The forums were taken down for a few hours yesterday to be updated. Changes to the user side of things are minimal, however lots of changes were made behind the scenes to keep things speedy and spam-free.
One side-effect is that some of you may still have old forum data cached, which could cause issues like certain forum features not looking right or working properly. A common example is the post editor being broken.
If this happens, please try logging out and then clearing your cache and history. If this doesn't work or if you spot what you believe to be something broken by the updates, let me know via staff at mapcore dot org and I'll see if there are deeper causes.