When a mesh is placed in the level with 0 Actor scale, lightmass simply refuses to move beyond the ‘Lightmass Starting Up’ stage.
This caused me a lot of headache for a couple of days where I left lightmass building overnight to see absolutely no progress whatsoever. I am confident this is a bug.
I was unable to reproduce this behavior in later versions of the engine. Would you mind testing this to see if the issue is resolved on your end.
What should happen is that if you have an object of zero scale you will get a message warning that a mesh has an invalid draw scale for built lighting.
I was using 4.13.2 and this issue popped up. I’m pretty certain I didn’t receive any errors or warnings in the build log/report or a map check. I COULD be wrong though, so there is that. I will double check to confirm.
I can upgrade my project to 4.15 and see if the issue persists, would that be helpful? (I believe that is what you are also suggesting)
Another thing to note is that my project has been migrated from 4.11 a while ago, (basically it started in an older engine version).
sorry for the confusion, what I am suggesting is that the issue no longer occurs in later engine versions and that in the fixed versions you should get a warning/error message.
I did reproduce your issue in 4.13 but we don’t log a bug report for cases like this since it has already been addressed.