I have no idea why, but selecting EDIT opens an app just fine, but clicking PLAY for an app results in:
Session ID: 10eae912-2069-4c92-b7fa-f7c88f7fa776
Do you mean you use the same account and in the same enviroment you can edit one app but can't play?
Do you save it after you make changes?
Is it can be searched in the apps' list?
Hope this could be helpful.