HaloMods "Classic" Read-only Archive

I'm trying to make a different mc. I'm using the first entity beta. I export the objects, change them, etc. When I import them, it says "input string was not in a correct format." So I try it with darkmatter. The only problem is, whenever I do it with darkmatter, it never changes. It adds it to the map, but then when I close and reopen, it's the original model. Has anyone had either of these problems before, and does anyone have any solutions? thanks.

It a bone problem I think, and if you use dark matter the MC will look awful due to dark matter screwing over UVWs. But if you do get a successful model injection, the animations won't work so it would kinda be weird.

Is there any way to counteract this? are there any programs that bring the bones with them? Could I just replace parts of the model instead of all of it?