Error Message while connecting thru SSMS
Cannot connect to <<SQL SERVER Machine Name>>.
ADDITIONAL INFORMATION:
Login failed for user '<<User Name>>'. (Microsoft SQL Server, Error: 18456)
For help, click: https://docs.microsoft.com/sql/relational-databases/errors-events/mssqlserver-18456-database-engine-error
Error Message in Event Log
Login failed for user '<<User Name>>'. Reason: Token-based server access validation failed with an infrastructure error. Login lacks Connect SQL permission. [CLIENT: <local machine>]
Solution:
Open the SQL Server Management Studio (SSMS) as administrator.