Invalid subnetwork connectivity, multiple controllers from different tiers found. Multiple subnetwork controllers were found associated with different tiers. This occurs when multiple subnetwork controllers are traversable to one another but do not have the same tier assigned.
If the tier associated with the subnetwork controller is wrong, modify the subnetwork controller by updating the role and re-creating the controller with the correct tier. Alternatively, if the subnetworks should be isolated, determine why they are connected and update your data so that they are isolated from each other.