I was trying to upload to the arcade but was constantly being told that I needed to export in the latest release of C2. Only problem was I was already doing that! I started opening the exported files and noticed in the Arcade.xml file that the version number was for r110 and NOT r110.2.
I think this is a bug because C2 is not writing the correct version number on export.
Here's my original post when I was suspecting a website error...
http://www.scirra.com/forum/topic60172.html