Where is the "share" Icon?
In help it says you can share a web page by clicking on the "share" icon. Which is on the far right of the bookmark, save, display, Mozilla Firefox start page, Start a conversation, share. However on my Firefox the "share" icon is not there. I'm trying to upload a screenshot, which I've done hundreds of times before on Safari, but it won't upload. How does one share??
Wšykne wótegrona (1)
Try to rename/remove the xulstore.json file in the Firefox profile folder.
You can try to reset browser.uiCustomization.state via the right-click context menu to the default value on the about:config page. You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.
If this didn't help then check for problems with preferences.
Delete possible user.js and numbered prefs-##.js files and rename/remove the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases.