You cannot load any files at all? Or, you cannot load that specific file? Could you load that file previously? If so, did you make changes to this file, and then saved it? The error message you received is a generic error that can cover a number of issues, but specifically, this error is thrown when the system cannot uncompress your file before it loads it into Modeling Personal Edition. Most times, it is because the file itself is corrupt. I would try downloading and unpacking the file again.