TempDB Owner

To avoid potential errors when running queries or performing maintenance tasks (e.g., rebuilding indexes) tempdb should be owned by "sa" or a renamed sa account.

Suggested Action

Set the tempdb owner to the system administrator.

How to Find the Name of the Default System Administrator (sa)

SELECT SUSER_SNAME(0x01);  
GO 

How to Changes the Database Owner to sa

ALTER AUTHORIZATION ON DATABASE::[WhippetWorks] TO [sa]
GO

Further Reading

ALTER AUTHORIZATION (Transact-SQL) | Microsoft Docs