I would absolutely love it if when an error message popped up, it was actually informative. Example: "can't keep roof and wall joined" or "can't join geometry" or "can't make roof"--this is not enough information, could Revit perhaps tell me WHY? I can usually trouble shoot, but sometimes I end up feeling the need to beat my head against a wall after trying 50 different things and always getting the same message.
Thanks!
Danielle