Trying to post my previous bug, I tried to upload a large-ish GIF in the post body but after a couple of minutes it was still sat at Uploading 100%, with Create Topic disabled:
I uploaded the image elsewhere and replaced the code in the post body, but was still blocked from creating the topic.
I abandoned creating the post, hit +New Topic to create another, to see this at the bottom:
And Create Topic still grayed out. Had to switch browsers to submit it.