I was getting exactly the same thing as in this thread, the original one on the topic. <a href="https://app.roll20.net/forum/post/10792007/black-map-on-firefox-ok-on-chrome" rel="nofollow">https://app.roll20.net/forum/post/10792007/black-map-on-firefox-ok-on-chrome</a> I suddenly remembered that I had been fiddling with my Firefox performance settings and shrugged and tried the instructions in the "Refresh Firefox" document. <a href="https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings" rel="nofollow">https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings</a> So far I haven't had any black screens in Roll20 in Firefox since the refresh. I will reply to this post should I have this problem again. (Currently I am running Firefox 112 on a 2021 MacBook Pro.) I don't know that I have the exact patience or sanity to figure out which setting or combination of settings it might have been though.