Since Firefox updated recently, the Firefox spell checker (right click) no longer works in Outlook 365 Web. It works in every other window (google, gmail, etc.). In other windows, I have all the correct options on the right-click menu: Undo Cut Copy Paste Delete Select All Check Spelling Languages> Inspect Accessibility Properties Inspect Element In Outlook, the Firefox right click menu has only the following options : Undo Cut Copy Paste Delete Select All Inspect Accessibility Properties Inspect Element The languages and spell check options are not there. I am a dual language user, and have dictionaries and language packs enabled for both languages in Firefox. "Spell check when I type" is checked, and I regularly use the "Languages" option to switch between languages in all windows. With the loss of this option in the right-click menu in Outlook, I can no longer check messages in both languages. It seems as if Outlook has disabled the Firefox spell checker. I can spell check using the Outlook spell checker (left click menu) but only in one language. I saw one solution (https://support.mozilla.org/en-US/questions/987216) which suggested I click on "Inspect Element" and see if spellcheck=false. It opened a window with many options (see screenshot), and I have no idea even where to look for "spellcheck=false" to delete it. The menu used to work properly in previous iterations of Outlook 365 and Firefox; I don't know what has changed, but I would be grateful for any help you can offer in helping me get the "languages" and "spellcheck" options back in my right click menu in Outlook 365. Thank you!