It looks like your issue is coming from your nav mesh:
LogObj:Error: LoadConfig (/Script/Engine.Default__RecastNavMesh): import failed for RuntimeGeneration in:
I haven’t had build failures with this before but maybe try rebuilding the nav mesh independently. Also check any settings for it they may cause issues. At least this potentially narrows it down and you could try Googling build failures in regards to the nav mesh. Sorry for not helping further, I’m at work at the moment!