Also because of that, some third-party mods conflict with Lain's mod. Very rarely is any other mod even needed with Lain's installed, tbh, since Lain tends to consult with the game's dev or dev team and include all improvements the devs are inclined to have added to their games, including certain... relationship patches, where appropriate. From the sound of things, you're trying to use a mod that messes with the Ren'py framework underlying the game. Since the game's ren'py files have been customized by the mod, again with the game dev's permission, you may indeed have an either/or situation between that mod and Lain's. Try again when Lain updates the mod for this game; if that doesn't fix the conflict, then the two mods are simply incompatible.