Hi Tsviatko ,
My LastSession.ffx has not been changed since 10th June 2016. In that time I have ran fiddler many times.
Fiddler having write access? Would that not be my user not having access? I've tried running as administrator and my normal account.
As for the Filters tab, I am not sure what is going on here. I have the following Hide the following Hosts:
www.telerik.com; nexus.officeapps.live.com; a.company-target.com;
But yet it still shows them when I click on the Actions->Run Filterset now.