Hey I'm having the same issue as i can see tons of ppl are having with the new update. My whole website was down for a while and at a very bad time too just from updating this plugin.
I tried another cache plugin, the W3 one because my site is really slow with Quick Cache deactivated and after an hour of trying to configure it my site actually got slower (probly bc i had it configured wrong but still)
So i redownloaded the older version of Quick Cache and am just going to use that until they come out with a fixed update. Although it's been a pain in the ass I'm definitely sticking with Quick Cache. The plugin is like magic for my site i swear. I just uploaded n activated the older version a few minutes ago and instantly my sites load times got 4 times faster with no complex configuring. The best by far IMO :D