Extensions not showing in Cinnamon settings

[Anubisone]

Hi,

today I decided to add more spicies extensions, especially Coverflow Alt-Tab 1.4.2 to Nadia

Downloaded the zip, unpacked it into:

~/.local/share/cinnamon/extensions/

then F2, restart by R and opened the Cinnamon settings to choose the extension. This extension is not visible.

weirdo, cause Blur Overview is showing up. Off course both folders are looking similar and are placed near each other,

I don't understand what's wrong.