According to this topic you opened on askubuntu.com, it could be that you see downloads that are already gone, and you accidentally cleared the list. Did you find the files after all?

Yes, I think that is it. I have very little on here, and I think I can access through FileManager on Lubuntu.

In unbutu you can see this link first i found one missing one lib

https://support.mozilla.org/questions/1080835

if you attempt to compile firefox is about 24 libs you need to downalod and install and maybe more but in the end is worth to try it.