Then you had the same experience I did...dunno what happened to grelber. Do you see anything in his method that might have caused his problem? (I never use my Dock, so I can't really relate to what he did.) My only thought is that he might have deleted ~/Library/Application Support/Firefox, in addition to deleting /Applications/Firefox. The former is listed, in my system, as having been modified at the same time that I installed the update.
Jon
macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365
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