Hello. I've encountered the same problem, and matter of fact keep encountering it sometimes when I start a new game. The first time this happened was 3 days ago when I installed the expanded warlock mod, encumberance comes in the form of all medium armour in the game being 3000kg.
I've deleted and reinstalled the mod and it got fixed. I have no idea if it's an actual bug of the game. Do you have mods installed ?
