Can't Open Database Error 3041

[MartinLiss]

I use the following DAO code to open a database

DBEngine.SystemDB = GetWindowsDir() & "WIZARD.MDA"
    DBEngine.DefaultUser = "MyUserName"
    DBEngine.DefaultPassword = "MyPassword"
    gsRWTSPath = App.Path & "\data\rwts.mdb"
    Set gdbRWTS = Workspaces(0).OpenDatabase(gsRWTSPath)

After literally years of maintaining this application I'm suddenly getting error 3041 which says "Can't open a database created with a previous version of your application". What in the world is going on? (I can't find any reference to the 3041 error in help.)