Crash / Freeze / null on 4.3.61

I don’t know what’s the cause, but when I run my game somewhere at the beginning I get this null exception and the whole engine freezes.

I have default recast graph with RVO simuator and few RecastMeshObj apart from that the scene is quite empty

That indeed looks like a bug. I have done some fixes related to that recently. So hopefully it will be fixed in the next beta update.