Why does ${this} happen on Google Hangouts in Firefox?

So, I've been using GH for a while, and for a while it randomly stopped working (and it still isn't working), I thought it'd work if I just waited, assuming it was an issue with the site that Google'd fix.
Nope.

The issue is that the webpage background is just black, and none of the clickable items on the page are functional (except the one that helps redirect you to other Google services).
It looks like this:

So, why is this happening??


Here's some info if it helps:

activePluginsAndExtensions = ["Adblock Plus", "VPN", "Google Translate", "Google Hangouts Web Messenger"]
deleteCookiesOnclose = true
sendDoNotTrackSignal = 1
protection = standard
version = 83.0 (64-bit)

I tried clearing my cache, but that didn't work.

Thanks in advance.
Cheers.