troubleshooting login failure when AD group seems to be fine
18456 (login failed) needs the STATE value to know why it failed. Look in the error log. – Sean Gallardy

Are you sure that if you added yourself tot he group that this sql server is connecting to a domain controller that has the updated info? If you have multiple domain servers it may take some time to have that info replicate a across to all servers. – Jeff A

This is the most comprehensive guide I have seen so far:


Troubleshooting Error 18456 by Aaron Bertrand


You need the state first to use that document. – SqlWorldWide

After you created the AD group and added yourself to it, did you logoff/login? AD Group permissions are only enumerated at login (e.g. the Kerberos Access Token). – John Eisbrener



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