Disclaimer: I have basically no knowledge of stellaris modding - I literally started trying to add mods yesterday. However, looking through this to try to get things running I'm pretty sure I've got it figured out since it's pretty straightforward stuff at this level.

1. Description:
This mod makes it so Gigastructural Engineering's virtual worlds and GCM: Planets Enhanced's asteroid, ice asteroid, crystal asteroid and dwarf planet all get their appropriate custom planetary capitals.

2. Updates:
It turns out it's not really out of date but, if I'm not mistaken, it does do things slightly differently than the Gigastructural Engineering mod. I'm not sure if it's deliberate or not, but with this patch only machine empires get the special capital for that mod's virtual worlds.
Either way, to make it stop showing up as incompatible, go to Documents\Paradox Interactive\Stellaris\mod and open ugc_1418548545.mod with a text editor, then change line 7 to supported_version="2.1.*".
If you also want to make it so all empires get the special capital for virtual worlds, it's pretty straightforward to do: open the Steam\steamapps\workshop\content\281990\1418133309 and open the zip folder there, then replace the contents of the 00_country_customization.txt file (it's a couple folders in) with the text in the following link:
https://pastebin.com/70b2DLLx