You received this error message if you attempted to use, edit, or delete an archived variable. For example, you have a program called Tetris and it is currently archived. If you try to run the program, you will get this error message. Let's say you have a list called LBOWL and it too is archived. If you tried to do something like dim(LBOWL) you will also get this error message. To prevent this from happening, you will have to UnArchive the variable so that you can use it.