This happened to me awhile back when I replaced my one headlight. Have no idea why it was saying it because the light worked just fine. -- the quick fix for me was to just flash the high beams, and they went back to normal, hope it's that easy for you too
I thought I was gonna go insane too. Turned out one of my brake bulbs was bad, the filament broke inside. So it came in/out of contact. Caused the lamp out light to come one. Check em good (Remove/inspect).
mine did the same thing bout 4 months ago. It was my right tail light. I replaced it then my left tail light went out 3 weeks afterwards. Now that ive replaced it i havent seen the lamp out light at all.