Can't edit certain files in Skullgirls Thread

Skullgirls 2nd encore is a game on steam, the problem when ot comes to the modding is that the game crashes if I attempt to alter the devs and characters related GFS files.

For the exportation I use Skullmod, specifically made for the exportation of those files.

So I would like to know what exactly is preventing the alterations from going through without crashing. I think it's important to mention that I'm simply swapping files between versions that have had no changes other than visual ones.

I accidentally post the same thing twice, sorry.