As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUXILIARY FUEL TANK COLLAPSED DUE TO VACUUM FROM FUEL TRANSFER TO MAIN TANK. UPON INVESTIGATION, FOUND MASKING TAPE WAS PLUGGING THE VENT STANDPIPE APPARENTLY TO PREVENT PAINT FROM ENTERING THE VENT TUBE WHEN THE TANK WAS PAINTED BY THE MANUFACTURER. AIRCRAFT WAS LANDED WITHOUT INCIDENT.