Yes, Gen 4 figures are Victoria 4, Michael 4 and their derivatives like Aiko. Thier UV maps were "unified enough" that they often get lumped together in things.

There are a couple of import processes you need to do to get things going...there is an "instructions" text file in the EZSkin zip. Read that file, then the actual import commands are in that top-left purple square button in the interface that kind of looks like a file list.

I just grabbed EZSkin3 yesterday and have used it fine so it's not the program itself giving you trouble.