I have been fighting a bit with my Fences 2 installation. Just a point to note in case it helps someone.
One of the problems I had was that Fences did not agree with Framework 4.0.
It would appear that it is a known problem with the clr.dll, which occurs on an ad-hoc basis (noted on Microsoft Support).
My Fences 2 did not have any problem with Framework 4.5, providing that Framework 4.5 was installed before Fences.