@all, the issue is being tracked by Scanner for MSBuild issue #589. We’ve released new versions of the scanner and the VSTS tasks to address the issue. Please let us know if you are still experiencing problems.
Please accept our apologies for the inconvenience.
Root cause: a property in one of our custom MSBuild tasks was marked as Required in version 4.4.1. The Scanner for MSBuild is embedded in the Azure DevOps SonarCloud and SonarQube extensions, which were re-released on Friday. The new versions of the extensions were minor updates, so they would have been automatically deployed by the build agents the next time a build using the task was executed.