Maps need lighting rebuilt (bug)

This has happened in a previous project, and luckily I had a backup of the previous map file, but this time, I do not,
lighting build completes, but keeps giving this, and only this message, all meshes that are static built fine, and works perfectly with lightmaps, no uv issues, I created 2nd unique UV sets in Max for all of them (and they also have no errors/warnings in the lighting build either).

And they have lightmap textures assigned/calculated fine, but after I change some scene objects from mobile to static, and vice versa, this flag does not want to be set.

The only real issue for me with this message, is that it is visible when I play, when I go to production mode,. I think the message gets suppressed. Which is fine.

The ligfhtmaps all work fine, but the message is incorrect, as all lightmaps have been built.

Hi Alwynd,

Could you please post your logs here so we can see them, you can find these at /projectname/saved/logs/. Does this message occur in a clean project with no additional content? Thank you!

Lighting build and Running the game log.
There are only custom assets in this game. (except the blue dude, for now…)
oh , wait a minute, you need to reproduce it… let me try…

Crap, I can’t recreate it. Well, no worries… maybe some one else will also experience this from time to time, when I have some free time, I will investigate, as long as it is not there in prod it’s fine with me…

This BUG has gone away with the latest release of Unreal Engine. 4.2.

Thank you guys!!! You guys friggin rock!

i’ve the same problem, in ver. 4.11.2 but i still got it
how i can fix it?
help me i need 2 days again before competition

4.17.2 and still have this. Building lighting results in the error that maps need lighting rebuilt. No other errors. Infuriating.