I do not expect from an extension like this to work perfectly on all web sites, and I would be happy to give it five stars IF there was not a major flaw: it interferes with some web sites and even with some other extensions.
For example it interferes with Google Maps, making it impossible to move the map with the mouse. The extension must be disabled then. And this is not the only web site with similar problems.
Also it interferes with an extension I use all the time: "Swift Selection Search", and perhaps others.
Basically, I have to keep it disabled, and enable it only if the need for it arises.

If the author cannot find a way to correct this problem, could he at least add a quick disactivate/activate option from the extension's icon.

While it does work, I found it is being blocked by Facebook for many things, or breaks facebook (firefox). I couldn't see the timeline stream past the visible screen rendered (no scrolling, just grey rectangles forever loading) and chats... this is strange... CTRL+V a link, image data (screen cap to paste) instantly closed the chat window in facebook.com 's messenger pop up window area.

So if you have a use for this keep using it, sure, but facebook is either blocking it or this is blocking facebook. So, use chrome etc for facebook. vice versa. :)

12-02-2022
So in firefox there is an add-on named:
Absolute Enable Right Click & Copy (Force Enable Right Click & Copy) v 1.3.8 updated May 25, 2021

Facebook blocks this and in the opposite direction it messes up pasting screen captures to people in Win10 Win11.
So if you press WIN SHIFT S and copy an area of your screen, usually you can go into messenger
and CTRL + V to paste that from memory into chat.

When this add-on is running (12-04-2022) it breaks that now with either a facebook javascript change on their side, or a firefox change, maybe a change with the add-on. Turn off the add-on and then reload facebook on the browser, and it will allow you to paste screen capture images you don't have to waste the additional step of saving as a jpg or png to your pc first.

Nice addon I liked using several years.
I left one star out actually just to point out a bug I stumbled upon this week : Facebook writing/commenting/posting has become really messed up and I realized disabling the addon solved it. Hope the signaling may help for the future
Cheers,

good

Love this NEEDED addon!!! I only wish that it could be set to automatically run on EVERY website. Why does it keep losing its list of sites so that I have to keep reenabling it?

Works for the most part but today I discovered it was the reason I could not send comments in Facebook. It stopped the function of the Enter button on my keyboard from sending, and instead made it work the way it works in MS Word and it creates a new line to type in.

This just stopped working (May 15 2021) for www.uol.com.br

Works nicely. Still works as of May 2021.

Could you release a new version which enables it on local files? Not only on http(s)://

I use its userscript version which work perfectly on Waterfox 56.5

SIIP