MSG_FILE_NOBACKUP

No backup copy of the original project file was created.

Indicates that the no backup copy of the InstallMate project file could be created. This message is preceded by a MSG_FILE_SAVE_FAILED message that indicated the reason for the failure.

Solution

If you want to keep a copy of your original InstallMate project file, then either use the File > Save Project As... command to save the current project under a different name, or use File Explorer to create a copy of the original .improj file.