What did you copy into the new mod folder? All mod folders need to have certain sub-folders, even if empty: /packs, /data/world, maybe even /custom. Download one of the many M2TW mods, and see their directory structure. You'll find they have a few empty folders which are nevertheless necessary, and just imitate that. We've successfully ported Paeninsula Italica to the M2 modding structure, and it works without a flaw.