Verify SQL Permissions and Roles

To use SQL authentication, the user must have DB Owner credentials.
The user must have the following permissions set:
Public and dbcreator server roles.
Both Database User and Default Schema must be defined as dbo.
Permission to connect to the database engine.
Login enabled.
In User Mapping choose the master database under which to create the Zerto database and set both db_owner and public for database role membership.

See also:

Recommendations

Considerations

Now continue to Migrating a Zerto Virtual Replication Database.