I am unable to boot virtual router instances, they time out after creating SSH keys step, CPU usage on the 'networking' process goes high on host machine until I disable the virtual router; OpenWRT boots but the same high CPU happens even when OpenWRT is idle with 0% vCPU usage and slows down network connectivity on host machine enough to kill my OSPF adjacencies.
The interesting part is that I don't even need to attach a virtual interface, the same problem arises with or without a virtual network adapter attached to the virtual machine.
Tried on both RB2011UiAS and PowerBOX, (MIPS) the same problem shows, I can't comment on other ROS versions as I started to play with MetaRouter with ROS6.37.3.

Is it the same problem as in my question http://forum.mikrotik.com/viewtopic.php?f=15&t=115422 ?

Is it the same problem as in my question http://forum.mikrotik.com/viewtopic.php?f=15&t=115422 ?

Looks like that, the same problem might be also affecting my OpenWRT image; it boots but CPU goes nuts and network connectivity start to lag destabilising the system.
The thing is that it is a production router and I don't have a similar spare device to test, did you find a ROS version that works?

did you find a ROS version that works?

I have upgraded my old RB450G from 5.26 (worked) to 6.37.3 (not working). I'm not going to downgrade 6.37->6.36->... until I find version that works.

It seems to be bug of Router OS, but who cares?