Okay, solved this one, the fix will be in the next release on the weekend. Current release is (2.5.37) so the one after that.
Contrary to my suspicions nothing to do with the controller (though the bug was easier to replicate while using one)
When selecting a mission, it was possible to accidentally load the mission twice. Causing all sorts of crazy problems, one of which was spinning.
Thanks for reporting the bug. :)
MichaelEGA
joined
Make games in my spare time