As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT PLAN NEARLY DROPPED OUT OF FMS WHEN APPROACH WAS BEING PUT IN. BEFORE DESCENT WINDS WERE ENTERED. THERE WAS NO NOTATION ON DISPATCH RELEASE REGARDING THIS. GROUNDED - YES. NO ACTIVE MSG ON OMF. PERFORMED FMCS OPERATIONAL TEST AND TEST NORMAL REF B737-9 AMM 34-61-00-710-801.