A video card software update is not a small thing. Its a disruptive process to anything that is running including (restarting) Windows Explorer which Fences runs in.
I suspect that when it is one, a restart of Windows explorer then a snapshot restore would resolve it. If not, perhaps just logging out of Windows would suffice. That said, if a reboot does resolve it, that may be what is necessary after a video card update - again, a disruptive process.
Stardock Support Manager