The context menu sometimes pops up under the cursor on the right side of the window, how do I fix it?
If the context menu can't get to the right, or above, or below, the cursor, it comes up underneath it. The reason this is a problem is that normally I right click and then click on my selection, but if the menu is underneath then the something is selected when I release the right button before I have a chance to read it. How do I fix this? It is a bad nuisance.
Opaite Mbohovái (1)
Firefox's built-in context menu, or a website's custom context menu?
Firefox's context menu should be offset so it is never directly under the mouse pointer. If yours is behaving differently, I'm not sure why that would be. In case the problem is a corrupted settings file that tracks custom UI settings, you could try renaming it.
(1) Open your personal settings (AKA Firefox profile) folder
Help > Troubleshooting Information > "Show Folder" button
(2) Switch back to Firefox and exit the program (e.g., File > Exit)
(3) Wait a few moments for Firefox to finish updating files in your settings folder, then rename localstore.rdf to something else, like localstore-bad.rdf or localstore.old. Alternately, you can delete the file.
(4) You're done with your profile folder and you can restart Firefox now.
A standard diagnostic to bypass interference by extensions (and some settings) is to try Firefox's Safe Mode.
First, I recommend backing up your Firefox settings in case something goes wrong. See Back up and restore information in Firefox profiles. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)
Next, restart Firefox in Firefox's Safe Mode (Diagnose Firefox issues using Troubleshoot Mode) using
Help > Restart with Add-ons Disabled
In the dialog, click "Start in Safe Mode."
If the menu works correctly, this points to one of your extensions or settings as the problem. One of the settings disabled by Safe Mode is Firefox's use of hardware acceleration for graphics.
Any change?