Stremio uses addons system in order to display content. Everything Starting from data about videos, videos streams and even subtitles is provided by addons.
There are two types of addons Community and Official addons. If you have a problem with Community addons that are not working there is nothing we can do about it as we don't control them.
If you have question about addons there is a reddit group dedicated to the community addons, you can find it here - https://www.reddit.com/r/StremioAddons/