Hello Leonardo,
Welcome to the community and thanks for raising this issue.
What version of SonarQube are you trying to connect to ? FYI we only support connection to a Sonarqube 7.9+ instance.
Could it be possible that the SonarQube instance was down when you tried ? My guess is that your SonarQube returned an error message that couldn’t be parsed. Could you try to access <your-sonarqube-instance>/api/system/status from your browser while authenticated and send us what is returned ?
Thanks