SQL Server principal "dbo" does not exist,
Solution 1:
I resolved this issue by setting database owner. My database did not have had any owner before this issue. Execute this command in your database to set owner to sysadmin account:
use [YourDatabaseName] EXEC sp_changedbowner 'sa'
Solution 2:
Do Graphically.
Database right click-->properties-->files-->select database owner-->select [sa]-- ok