Internal Server Error The server encountered an internal

When I try to upload my new purchase, i get this. I have not had problems uploading any zip files in the past. Please advise?

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.