That does not sounds like an error you would get from implementing a script... Did you check if the maps are even in the data folder of the project? If the maps are in the data folder, then you can get them back, however, if there is no map data in the data folder for that project, it's likely you forgot to save or something and the maps are lost.
Only one other thing I could think of is that you saved the map data else where, but how you would pull that off... I have no idea.