FAQ: Why do I get the warning ''unexpected file format'' while restoring loading a project in the Engineering Studio?
Sometimes it can happen that old/deleted/corrupted screens are still in the project-SQL directory (C:\ProgramData\COPA-DATA\SQL[VERSION]\[PROJECT_GUID]\FILES\zenon\system\pictures). Once you know the corrupt file in this folder you can delete it and restore the project again in Engineering Studio.
To find out which is the corrupt screen-file, in the Engineering Studio add the column "File name" in the Screens detailed window. Normally, the corrupted the screen does not show a name in the screen list. The filename linked to the screen with a blank/empty screen name should be the file triggering the warning message.
Alternatively, try and error deleting the corrupted screen-file in the above folder is only recommended if you have a second backup of the project.