This is a follow-up to my original post:
http://forum.mikrotik.com/t/v5-9-upgrade-warning/52221/1
If you upgraded to 5.10 or 5.11 and had your meta-routers change all their ports, ie: ether1 became ether3, etc…
then be careful when upgrading to 5.12.
They did fix the issue, but if you’ve changed the ports in your meta’s to compensate for the 5.10/5.11 bug, they will enumerate correctly and change back to ether1, ether2, etc…
You will have to go back in and change your ports.