As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAV SMOKE MASTER WARNING FOR FWD LAV DURING CRUISE, WHILE PAX WAS OCCUPYING LAV. EXTINGUISHED ONCE PAX EXITED LAV. REMOVED FROM SERVICE. C/W E175 FIM 26-14-00-810-803-A, NO ABNORMAL SMOKE/SMELL PRESENT. PERFORMED SMOKE DETECTOR SYSTEM TEST IAW E175 AMM 26-14-01-700-801-A. TEST PASSED. LAV SMOKE MESSAGE EXTINGUISHED ON EICAS. NO FURTHER DEFECTS. RETURNED TO SERVICE.