I use Firefox 60.8.0esr-1~deb10 which is a package in Debian 10.0 (stable).
I have had the following problems with Firefox for several days.
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The following problem suddenly went away today. I did not do anything. But
History Cleaner was last updated on August 9, 2019. Today!
I go to the page:
https://addons.mozilla.org/en-US/firefox/addon/history-cleaner/?src="">
I click on "+Add to Firefox". A small box appears at the top. I click on
"Add". It hangs. The browser console says:
"PopupNotifications._onButtonEvent: Button click happened before the window
was focused"
The "Cancel" option in the box also fails.
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Click "Help", then click "Troubleshooting information". A few lines down is
a box that says "Open Directory". Nothing happens when I click on the box.
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Go to the Refresh Firefox page at:
https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings
There is a box saying "Refresh Firefox". Clicking on the box does nothing.
Thanks.