I realize this is an extremely late response, and a lot has changed since then (full release for one) but I just got the same identical error. I've disabled big bags to see if that makes a difference. But since you said that you renamed it, shouldn't that mean that I shouldn't get the error in the first place?
It's not a disaster, I'm not that attached to the big bag mod, but it took me awhile to figure out which mod was giving me problems.
The game loaded without any errors, with big bags disabled. So that worked!