Starting from a small project which raises a compiler warning (CS3021), analyze the project in SonarQube. Export the project, and then import it into another SonarQube server (where no C# projects had previously been analyzed).
The following error is raised on Project Import:
Can not import, the following rules are missing: external_roslyn:CS3021`
What should happen instead is that the issues should be treated the way they were on initial import into the original server (rule creation, &etc.) so that the project appears intact after import.