Unknown error code 5 while restoring.

My iPhone 5s (in recovery mode) continues to tell me to connect to iTunes and when I do, "Your iPhone can't be updated; you must restore to factory settings" comes up so I restore. It does it's thing and when it prepares the phone for restore, unknown error code 5 pops up. Restoring from iOS 8.3. Already looked at Apple Support and there's nothing troubleshooting error code 5.

Any help?