For a week or better I have been unable to download anything through my Firefox browser, I have refreshed and uninstalled Firefox (I had to reinstall through another browser) in an attempt to fix this issue to no avail. I cannot download from verified sites, nor am I able to download Firefox's own extensions or themes (when I attempt I get an error telling me to check my connection, screenshot included).

I would like to be able to use Firefox normally again, with the ability to download files and install my extensions restored.