Error importing a blog snapshot

I'm trying to import a snapshot from to and gives me the following error:
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.
Apache Server at Port 80

How I can fix it?