1) I have Firefox (not sure how to tell what version though) and have been using it for years intalled on my Linux operated system. (can you tell I'm not a techie?? : D : P)
2) Yes, just did, but nothing changed.
3) I tried installing Google Chrome but it didn't work. : /
To answer the rest of the questions...
I can't upload any photos, not on public posts nor in my private messages.
I haven't received any error messages at all.
This is a new issue for me; the first time it didn't work was on May 23, 2015 when I was trying to upload a few photos for my friend to see in private message. I tried again on 6/19/15, but still the same thing. I typed out my message like I usually do, then pressed the Upload a File button. Once that box popped up, I clicked through my folders till I got to the one I wanted, but when I opened it, it showed up blank, not letting me see any of the photos I know are in that folder.
Let me know if I missed anything or wasn't clear. Thanks so much!