Without specifics (and often code), it's extremely difficult to know what may be happening or understand what the 'weird stuff' is.
I can say in a general sense that most of the errors I've run into involved some needed code changes to accommodate the newer Studio framework and a few that involved coding errors on my part that were permitted/bypassed in AGKV2, but not in AGK-Studio. Granted, AGK-Studio seems a little less inclined to provide error messages for certain things, so it may help to review the Windows event log and look at the application errors filed there to determine what kind of error may be occurring. Also try remming out some lines of code to try and further pin down where the issue may be occurring to explore it further.