Having difficulty playing so far - Took the files out of the internal folder and right into the zip file didn't help, Game still doesn't recognize the mod. I'll try in some other versions.
Was this designed for a certain version?
Ooh, I may have found it. Or just something else.
"m_u_settlers.xml" for the Merfolk Settlers shares it's name with the Maskling Settlers. But I still don't think that would stop it from recognizing the mod.