I understand you're having troubles you did hte film strip entered in your URL or Share they both should create the video, also can you post a URL and it changes to the blue clickable ( I see you got a link in and it works) link? I mentioned @<b><a href="http://www.goprofanatics.com/forum/members/aj.html" target="_blank">AJ</a></b> maybe he changed the post count it was right away for the longest.
Go to settings
Go to general settings
Change Message Editor Interface to another option
Check if you can post vids/pics - if not- check second option - if not
CHANGE IT BACK to the option it was at the beginning
Hope you understand, little strange but after that I could post.