asked
SQL Authentication sysadmin login connects public does not
Created a User account with SQL Authentication on a SQL Server 2008 R2 Clustered Instance. When the user is added to sysadmin role, the account can login, otherwise when role is set to "public" and at the database set to db_owner the error is logged: Login failed for user 'xxxx'. Reason: Login-based server access validation failed with an infrastructure error. Check for previous errors. [CLIENT: xx.xxx.xxx.7xxx] Advice will be greatly appreciated. Feel like I've tried every possible iteration and am concerned it has something to do with the cluster. This is a pre-prodcution installation.
I'd recommend checking that you have UAC turned off. This has been known to cause problems (and this specific error message). Alternatively run SSMS as an administrator and then attempt the login.
Finally found the right answer! It is the permissions granted to the Public Role. It was not allowed to connect.
If you have find it out yourself, then please mark your answer as accepted.
I found this:
http://dbamohsin.wordpress.com/2011/09/06/token-based-server-access-validation-failed-with-an-infrastructure-error/ It seems pretty close to what you are experiencing.
