Alright so the first two problems have been solved. Reinstalling it did fix the first issue. The second problem I had to manually set all my static meshes to Nanite enabled, in order to directly load into my level.
Now building the lighting is still a problem. I got some more info in the crash logs now.
This is now the only problem I have at the moment. (Ive been told to do build lighting at the close end of the level design… but Im adding so much I like to stay on top of it. I have so many assets already placed… I cant seem to narrow it down for a solution.