This can happen if you are using an older version of SSMS trying to connect to a newer version of LocalDB. Ensure your SSMS version is up to date (SSMS 18 or 19 is recommended for modern LocalDB versions).
The default instance is usually MSSQLLocalDB .
Launch your Graphy
This can happen if you are using an older version of SSMS trying to connect to a newer version of LocalDB. Ensure your SSMS version is up to date (SSMS 18 or 19 is recommended for modern LocalDB versions).
The default instance is usually MSSQLLocalDB . sql server management studio connect to localdb