The answers above are correct, but let me explain why you are running into this issue.

Basically, the User entity currently has relationship with both Suburb and Role, so you can not have CASCADING delete which would cause a conflict.

Let's say you delete a Role and it will also delete the user, but then how about the Suburb? You can see now the Suburb is not tied to anything, so that is why EF Core prevents this behavior. You have to specify NO ACTION so when a role or suburb is deleted the user won't be affected. This is a very common problem when an entity has relationship with multiple others.

In this case, it would not make sense either to remove the user just because role or suburb no longer exists.