Hi,
I am trying to locally install a CMS for my website. During this installation process, it shows me an error "User or role does not exist in the database.
Screenshot of the error:

Here's the screenshot of the login properties from Management Studio (Properties of the user Sarin)</p>

Screenshot showing the database user properties: i.imgur.com/9FKfa.jpg
User mapping: i.imgur.com/ubPAe.jpg