That Unknown Client Tag error means that the clients wasn't registered in the SoftwareClient table in that database. You can delete that client registration and register again using the client key and it will add the client into that database SoftwareClient table.
Typically when refreshing instances from other databases, step 3 in the blog tells you to backup that table and restore after the database restore.
Moving or Copying a TariffShark Database – TariffShark Blog
But if that wasn't done people just register again to the instance and that will work. Friendly name has to be unique in that table so if it exists use a different Friendly name.