Lighting build stalls at 93%

Hi, Just updated to 4.8.2, (didn’t get a chance to play around too much with 4.8) but I am having an issue the build lighting seems to have stalled, simple lighting too, as I added a point light to default third person map and build lighting, and it stalls at 93% - any reason?

What exactly do you mean by “stall”?

Try clearing swarm’s cache (on of the options in the menu, I am in my phone at the moment, so I can’t look).