Taking a Screenshot; Windows > Start > search box > Snip. Select Snipping Tool. Use a compressed image type like PNG or JPG to save the screenshot. Save the picture(s) to your desktop. Press the Reply button. Then press the Add images; Browse button.

Make sure extensions.screenshots.disabled = false on the about:config page.

You can open the about:config page via the location/address bar. You can click the button to "Accept the Risk and Continue".

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

extensions does = false. switched it to trua and back to false and it did not return. just since yesterday's upgrade it's been gone

Note that in Firefox88 "Screenshot" has become a standalone toolbar button that you can add to the toolbar via customize mode.

• https://support.mozilla.org/en-US/kb/take-screenshots-firefox
• https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars