Hello @Step,
Thanks for raising this issue. It appears that you also have CodeScan installed as the error suggests. CodeScan is a fork of SonarLint and we received reports in the past that they don’t play well when installed together.
This time I decided to open an issue on their side: Make CodeScan compatible with SonarLint · Issue #6 · codescan-io/sonarlint-intellij · GitHub
In the meantime I’m not sure there is a workaround, except using one or the other, by either installing/uninstalling or enabling/disabling one of them.
Hope this helped