Hello
I was upgrading my RB751 the other day and put the entire set of files on it - including UPS, GPS and others the hardware does not have / support.
When I restarted the router, all seemed fine (it worked) until I connected WinBox. WinBox downloaded the new plugins and then the router crashed. WinBox also would come up with no data listed under any management window and it seemed even that just looking at any window would crash the router (not sure about this though).
After troubleshooting for some time and realizing my mistake, I removed the additional packages (from the command line) and the router still crashed when WinBox connected. The only thing that stopped this was to delete the WinBox plugins for the packages I removed form the router, after which it started working with WinBox again.
The same behavior was produced by The Dude - if The Dude was set to monitor the device as a MT router, after installing the wrong modules on the router, The Dude caused a crash. The only way I got past that was removing and re-adding the node in The Dude.
I posted this so at least you knew and could investigate the problem. Please let me know if you need any more info!
Adrian