I made an app which turned into a nightmare when trying to save as a standalone... It told me about stacks that were already in use and asked me about if I wanted to save them first. The problem was that most of them was internal stacks of Revolution Studio. I had to dismiss at least one hundred dialogs in order to get through the "compilation", and in the end it didn't work anyway...
I then tried to clean up my application by removing all cards and substacks, not used yet (not implemented yet), renamed all datagrid cards and saved as a new version. Now my app saved as standalone in just a few seconds. But the standalone never started. There was no bouncing icon, no error message, no nothing!
I then re-saved my app and changed the name to remove all Swedish characters in the stack's and standalone's name (as I know they will give a lot of systems and programs the hick-ups). Now my app actually started but my windowShape didn't work. My window came up with a pattern of blue and white pixels.
I then removed all references to the window shape and imported it again and reset the windowShape to my "new" image. And now everything remaining are my own bugs

Conclusion:
- 1. Revolution Studio doesn't like Swedish (non ascii) characters. Maybe RunRev missed to use the uniDecode function somewhere
2. If you have a stack created in an earlier version it might be a good idea to resave it under a new name in the new 4.0 version.
3. If you use a windowShape Revolution Studio can "remember" the shape even if it's not in your stack anymore.
...and maybe someone with more inner understandings of Revolution can share some light on the subject.