This may help anyone else who has recently run into the issue with the 1.0.6.3 version of Frosty.
I got this error after I tried to add a .dai mod I already had added by mistake. The program crashed with a bunch of jargon errors, and I wasn't able to open it again without this same error. I tried running as admin, redownloading Frosty, deleting appdata files, etc. with no success. I decided to go ahead and play the game without my Frosty based mods and realized my game was now broken. I verified my files and 8 of them were suddenly missing when only an hour before I was playing the game just fine. I assume the issues are related. After getting those files back via Steam, out of curiosity I opened up Frosty to see if I could get it to open without error, and it did. Mod list popped right up in 2 seconds and was able to run the game with my current mods.
tl;dr - Try verifying your game files if nothing else works, because Frosty broke some of mine and caused this error.