The new version 6.1 was installed and when clicking on the "Test Link Tracking Database Settings" from the SharePoint Services Configuration, the error appears:
"Failed to log into the specified SQL Server with the supplied credentials" during test connection to Link tracking
The Windows account has db_owner role to the Link tracking database.
There was an issue in Test Connection in the RTM (188.8.131.526 build) but it does not affect migration.
There was a fix released. Contact Support for a latest version of the tool