Every time I installed and active SnapShot, it causes all of these problems (and maybe more):
1. Blocks me from installing new plugins
2. Blocks me from running the Hummingbird Speed Test
3. Stops me from updating Wordpress and other plugins
There was one other problem that I can't remember as I write this.
And I'm sure SnapShot is causing the problems because as soon as I deactivate it, I can do all three things. Also, earlier this week, I thought that it might have been caused by something at my hosting company. But they checked everything and there was nothing wrong on their end. They disabled all plugins and I could install plugins again. So, I reactivated plugins one by one and the problems started again when I activated SnapShot.
I really like to get this to work because I see the advantage of having it run on my site.