Trouble shoot mirrorign endpoint problems

- list all endpoints: select * from sys.endpoints
make sure that the name of the endpoint is the same on all nodes incudling the witness.

- If the endpoint is having a wrong name, drop it:
drop endpoint mirroring

- If needed, create a new endpoint:

CREATE ENDPOINT mirroring
STATE=STARTED
AS TCP (LISTENER_PORT=7022 )
FOR DATABASE_MIRRORING (ROLE=WITNESS)

- Grant connect right to the user:
GRANT CONNECT ON ENDPOINT::mirroring TO [domain\Username];


- make sure that the correct user owns the endpoint:
ALTER AUTHORIZATION ON endpoint::mirroring TO [domain\Username];

In wrong endpoint is used or the user is not having connect rights, mirroring will not work with automatic failover.