Kifu

you are going to want to first get the Mayberry 1.5.1 Patch. https://mega.co.nz/#!X05zBKLL!STWaWi-rdsKfIirof5s0-WsGH2dnTyLcxfFroJIH4uY once you have done that you will want to take the patch and place it in your Mayberry Mod 1.5 folder. now that you have done both of those things you are good to go and can play MP with out any issue.

Manhattan mod takes a LOT of your system. I am willing to bet your going to need a bit more POWER from your system... and I don't mean the kind coming from the wall. Oh and a Graphics card helps. I could not play the first Manhattan mod with out one. Best of luck!