[Jonathan90]

I had the exact same problem its something to do with not unloading from memory after you close firefox its still in memory and i could download enything must be a bug close firefox go into taskmanager and delete process of firefox.exe then try again

---------- Post added at 15:05 ---------- Previous post was at 15:02 ----------

if that fails reboot and reset everything for firefox or go one step better and delete the firefox folder from application data. seem to fix it for me