I think I know what happened.:
Block Fuel in the W&B page was incorrectly set (I have it set to imperial - this is an IniBuilds EFB issue) KG while the fuel figure where you put the load was correctly set to LBS. However, I tried putting in the KG figure. I believe when I set the ZFWCG and the aircraft made all of its calculations, it panicked when it saw the incorrect and small KG figure and froze the whole airplane.