I have found the culprit.
When I let my spouse install VP from Gazebo (
https://mega.nz/#!Xd9hiLqB!jzoyD9XnjCc4gBRIg1TTX16TO3b_sjG0h4JgNRx2-N0 ) and copy CvGameCore_Expansion2.dll from it in the next two locations, it works!
D:\Steam\steamapps\common\Sid Meier's Civilization V\Assets\DLC\MP_MODSPACK
D:\Steam\steamapps\common\Sid Meier's Civilization V\Assets\DLC\MP_MODSPACK\Mods\(1) Community Patch (v 88)
(D: depends on what drive you installed civ V on)
So somehow when copying or archiving CvGameCore_Expansion2.dll in a .rar file it fails.
If any higher knowledgeable power here can tell me why and how to avert this, I will be more than happy to upload a full working MP Modpack. Until that happens, people can download the modpack from the link above and use this workaround.