Why did you allow your users to upgrade then?
Because Mozilla pushed the update as part of the normal daily updates, without even so much as a pop-up warning that it was going to happen.
The same thing happened to me. One afternoon last week, one of my kids comes to me telling me his computer is acting strange. After much digging I discover two things: First, the computer has some kind of malware on it that is doing some naughty shit. Luckily, I have the kids computers segmented from the rest of the network and each other, so the damage is contained. The second thing I discover is that Firefox on the kids computers automatically updated to version 57. My kids cannot have done it because they do not have permissions to install or run unauthorized software. I checked my own machine and sure enough, it had automatically updated to 57 as well. Any other time, I might not have cared so much, but this time it was criitical because Firefox 57 is not compatible with NoScript yet, and so the #^@&ing idiots at Mozilla thought the ideal solution to that problem was to just do the upgrade anyway and ignore the fact that NoScript did not work, by simply removing the Add-on altogether. Worst of all, all of this happened silently. Those imbeciles caused my sons computer to get owned by taking down an important layer of defense I had constructed to keep those computers safe.
The important lesson here is that NoScript is more valuable to me than Firefox, and having been so burned once, I will never again touch another Mozilla product as long as I live. NoScript was the only thing keeping our computers on Firefox. Since I obviously cant trust Mozilla to do the right thing, I have no choice but to move to an alternative. I don't like ScriptSafe as much as I liked NoScript, but Firefox is forever off the table, and that leaves microsoft or google.