As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MOMENTARY LOSS OF BOTH FMC'S VTK FLAG ON CAPTAIN SIDE. LOSS OF FMC ON MENU PAGE OF MCDU. FMC'S RECOVERED WITH NO PILOT ACTION. GROUNDED - YES. NO ISSUE - FMC NUISANCE VTK ERROR-RECOVERED OK. OPS NORM REF. B737-800 AMM 34-61-00-860-801.