I used to use an extension called Right-To-Click for websites that either disable selecting text or prevent me from accessing the right-click contextual menu. The addon was enabled on demand as sometimes restricting what text can be selected is helpful as it limits it to the content instead of the other site-related junk (look at the right-hand panel on this forum for an example, and image highlighting that stuff along with the text you are trying to quote when doing a multi quote).
I've been using an extension called "Happy Right Click" as a replacement.
https://addons.mozilla.org/en-US/firefo ... ox-browser
However, for the last couple months, a bug has appeared. Most of the time when I middle-click by pressing down on my mouse wheel to open a link in a new tab, two duplicate tabs open instead of just one. I finally traced it down to this extension.
So any other suggestions on alternatives to Right-To-Click or Happy Right Click?
Again, the main feature is being on-demand, and fixes sites that get cute disabling the right-click context menu or selecting text.
Those that ask how I'm sure, [spoiler]
I though my mouse was going bad, but I finally did some testing and realized this doesn't happen in Chrome, and it happens with multiple mouses. Starting in safe mode or creating a new profile fixed the problem, but in the latter case, reinstalling all my extensions caused the problem to reoccur.
Doing a binary search disabling extensions yielded "Happy Right Click" as the culprit.[/spoiler]