02-15-2018, 04:27 PM
Your problem there is that MegaMod is made with mods for Banished version 1.0.6. There were a fair bits of tweaks between the 1.0.4 Banished version (early days of modding) and the next couple of patches.
GOG has the 1.0.7 version of Banished so if you have a valid key you should have no issue getting the updated game from there.