I will point out that it took a couple of minutes, using Arca Noae Package Manager, to get this right, and I used my latest WarpIn installer (at Netlabs, and Hobbes) to get Firefox 38.8.0 properly installed. The WarpIn installer no longer makes any attempt to verify that the user has the proper DLLs (and other things) installed. ANPM (recommended), or the YUM command line, will do that properly. Trying to do it yourself is probably possible, but I suspect that it will turn into an exercise in frustration, before you figure it out. It seems that even the developers don't know what you need.
FWIW, I installed FF 38.8.0 last night, and it seems to be working well. The only anomaly, that I have noticed, is that it insists that I haven't used FF for a while, it welcomes me back, and it offers to clean up Firefox. I haven't let it do that, yet.