HaloMods "Classic" Read-only Archive

when i try to apply a patch a get a screen saying this program has encountered a problem and needs to close and my maps are clean and i have version v3.20

It could just be the way you are trying to patch it or the patch was made wrong. Try a different mod with a .serenity and apply it to see if you get the same error. If you are then it is most likely the way you are trying to apply it.