Troubleshooting Login Failed error messages
Logon Error: 18456, Severity: 14, State: 11.
Login failed for user <Server name>\kalyan'. Reason: Token-based server access validation failed with an infrastructure error. Check for previous errors. [CLIENT: xx.xxx.xx.xx]\
If you face the above error for windows user which has sysadmin role probably there might be issue with UAC, Please run the SQL Server Management Studio with Run as Administrator.
Other reasons for this issue is the login might not exists on the SQL Server on which you are trying to login.
If you are able to see that domain login exists and still you are getting the same error then you need to drop and re-create the user at SQL Server level.