Swarm Kikcoff problem

I’ve been trying to build my game for 10 days, I’ve re-installed 4.26, downloaded UE4.sln… ran UnrealLightmass, Exported map to other project, decreased amounts of objects.
Here how it went:

  • I could render in 3 hours then it suddenly altered, 3 hours - 8 hours - 2 hours (only rendering)
  • Then (still same map) 1 out of 3 renders built the project 2 crashed
  • Then now swarm kicksoff and cannot render this map, I copied map to other level rendered just fine but then same thing happened to that map too.

I’m having hard time to understand does this make sense? This rapid changes in rendering time, and 2 exact same maps 1 can be rendered other not, then this?
What I tried:

  • Downloaded main files from github ran UE4.sln and built UnrealLightMass(fail)
  • Found UnrealLightMass and ran as manager (fail)
  • Migrated Map (fail)
  • Created same map including same objects(Worked 1 time then still the same thing)
  • Reinstalled 4.26 (still fail)
  • Created another map with same objects deleted everything (if same map is copied problem still occurs, but if you open a new level, you can build it 1 time then still same problem)
    Any advices?
    Thanks in advance.