Update: It worked! Thank you very much! 
Hello I am havin gthe same issue where my good islands are Spatial hash and my broken island is hashSet.
it wont run a memory calculation it will get stuck on 4%.
the Runtime Has set looks very different form spatialhash
Hey RenoRivsan,
Yes its a bit of a curveball.
Are your HLODs displaying properly in a play test ?
When did you last build your HLODs ?