I doubt skin.helper.service have been updated for Leia(v.18) since there has been no action on its github repo for 7 months. And that was to change the README.txt to mention he needed help to maintain it.
ERROR: Requested path http://download.osmc.tv/kodi/addons/krypton/script.skin.helper.service/script.skin.helper.service-1.1.3.zip not found in known repository directories
@david7 That error has nothing to do with skin.helper.service and is a generic error saying the the addon can’t be found in the repository. I’m guess you’ll get this error no matter what addon you try to install. Try installing any other addon to see.
I had the exact same problem when I upgraded to v18, deleting the .kodi directory fixed it, but means you need to set up your Vero again.
@joakim_s skin.helper.service works fine under Leia
I’ve just noticed that Kodi v18 seems to be installing an old version of the skin.helper.service that is not compatible with v18 (maybe this behaviour is new and therefore it’s not an issue for those who’ve installed a newer version before ). The Kodi repo does not seem to be up to date atm. Installing the beta repo of the maintainer/coder of that script and installing the newest version from there should do the trick: