As answered before, this addon is not ported to KODI 18(Leia)
You can ask skin developer, or stay on working skins
It could not be fixed by CoreELEC developer
Just FYI - the dev for that skin has recently released a Leia Alpha release in his repo that works pretty well.
noxx When installing the skin, just make sure to select the Leia version of the embuary skin. I'm using it on 2 of my devices, and it is fairly stable.