[Media_Player]

I saw this posted on the Amber section by wookielover.  I tried it and it seemed to work well for Black Glass Nove too.  In case anyone else is still trying to use this skin.

You can update the skin's addon.xml file and it will work with Omega. 

Navigate to your addons folder -  .kodi/addons/skin.amber
Edit the file addons.xml
Change the line "xbmc.gui" version="5.15.0" to 
"xbmc.gui" version="5.17.0"

restart kodi and you can enable the skin.

[Arkady1964]

Hello
Information, in the --- repository there is a Black Glass Nova 21 skin running on Kodi 21 Omega available for download in the "Look and feel" section. --- repository:

[Karellen]

repository there is a Black Glass Nova 21 skin running on Kodi 21 Omega

Please do not link to repositories that also provide banned addons.
I've removed the link from your post.