Can anyone help me to repair this issue, before I try to recover/reinstate my many missing fences?
My best advice would be to try to boot Windows into safe mode or safe mode with networking , that's typically the way to deal with stuff like that ,
and then try to install the version 3.09 on top of old via safe mode , then boot into normal mode and see if it helped (eventually see if you can restore settings from a previous saved snapshot if need be)
same goes if you just want to un-install - which I would not recommend as I do not know if your snapshots and other settings will saved...
Ref. : Start your PC in safe mode in Windows 10 :