Cannot Create Database Diagram in SQL Server 2019 Database

Question

I have a SQL Server 2019 database that I restored from a SQL Server 2017 backup. It has diagrams present in the System Tables dbo.sysdiagrams table, but they are not visible. If I try to create a diagram I get an error:

What is the problem and how do I fix it?

Thank you,

Answer 1

A shot in the dark...likely a good one. Check the database owner to make sure it is set. It might have been a login that is not valid on this instance. Not having a owner can cause access issues in SSMS.