Symptoms
Assume that you use Microsoft SQL Server 2017 on a Linux host that is joined to an Active Directory child domain. When you try to create a login that is based on a Windows domain user that belongs to the parent domain, you may receive an error message that resembles the following:
Msg 15401, Level 16, State 1
Windows NT user or group user_name not found. Check the name again.
Resolution
This fix is included in Cumulative Update 4 for SQL Server 2017.
About SQL Server 2017 builds
Each new build for SQL Server 2017 contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for SQL Server 2017.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Active Directory authentication with SQL Server on Linux
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