GitLab CI Runner registration problem

Yesterday, I was running into an issue while trying to register a new GitLab CI Runner with our self-hosted GitLab instance. While that worked fine about 2 weeks ago, it did not this time. The only difference is, that we recently upgraded to version 15.9.2 of GitLab.

The gitlab-runner register command failed with the following warning:

WARNING: Support for registration tokens and runner parameters in the 'register' command has been deprecated in GitLab Runner 15.6 and will be replaced with support for authentication token.

This led me to believe that the refactoring which is currently done by GitLab to migrate from registration tokens to authentication tokens caused the issue. However, that was not the case as the hint is just a warning.

After wasting a few hours testing different approaches, I came across 2 settings in the GitLab Admin UI. In the CI/CD section, you have the following two options:

I enabled both "Members of the project can register runners" and "Members of the group can register runners". I was under the impression that the UI for my regular GitLab user would change and let me register a new runner as a user. But that was not the case and I was not sure if these settings affect anything.

Actually, they do. After enabling both of the options, I copied the registration command instructions and executed the command on the server. The runner got registered and I could continue with my work.

Not sure if this is a glitch in the 15.9.2 release or if it happened on purpose.