I have found two Error ("! Game_Installer_Designer_1.5").
A: sometimes, not always, are, after loading a project, the stored data inputting away and you have to re-enter everything.
B: If I go to "Editor -> Main" and fill out everything and then go to "Interface", I get this error:
http://i.imgur.com/MNFHPF6.jpg
Operating System: Windows 8.1 (including all updates.)