Here I purchased it and I can't even download it.
The download is always freely available before purchasing. You are normally supposed to download first, install, try it, and then purchase it.
Still can't download JFK. Any other ideas? Obviously the the server is having problems because all the other sceneries download without a problem.
The server are not having any problems, and the server logs shows there are 14 persons downloading the JFK V2 full installer and 9 persons downloading the update in this very moment and of course, nobody else has reported this, so the problem is surely on your side.
Most of the other installers are on not hosted on mediafire, only JFK V2, CYVR and GSX are. Can you download GSX or CYVR ?
If you can't download those too, that clearly indicates your system has a problem with accessing mediafire.com, all the possible steps you can check were already indicated in my previous message. Are you SURE you cleared both the browser cache AND all cookies coming from mediafire.com ?
Another possible (although unlikely) cause, is that your ISP has blocked mediafire.com domain, or that your IP has been blocked, not because you did something wrong but, if you are having a dynamic IP, someone else might have abused from it, so now that you got that IP, you can't download anymore from it. Which is why I suggested to restart your router, to get a new IP. Of course, if you have a static IP, this doesn't apply.