It looks like you're having some problems activating RubyGems, as well as unable to initialize the theme-check-language-server. It's possible this is due to issues with your Ruby environment setup. Some factors that this could be due to are:
A mismatch between the expected Ruby version and the one being used.
A missing or misconfigured gem that the language server relies on.
Conflicts between multiple Ruby installations, leading to the wrong version or gemset being used.
To resolve the issue you should check that the Ruby PATH setup, ensure the correct Ruby version is being used, and verify that all required gems are installed and accessible.