Now wait a minute, according to my Releases page, Fx 126.96.36.199 just came out on Monday, November 26th. Two Firefox releases on the same branch in the same week? It could happen. Seems to be a serious regression in the recently release version 188.8.131.52 build earlier this week.
From Mozilla Links:
A bug in just released Firefox 184.108.40.206 affecting an important <canvas> HTML element interface (.drawImage) has prompted Mozilla developers to rush a new update that fixes this bug that affects several web sites and extensions (FoxSaver, Fotofox) that rely on it to deliver the intended experience to their users.
From CyberNet News:
Why is this such a big deal? Extensions such as FoxSaver and Fotofox use that property for displaying images, and without it the extensions will appear to be flawed. FoxSaver even warns users on the site not to upgrade to Firefox 220.127.116.11 if they want the extension to work as expected.