Doing this will bring you to the hidden Firefox configuration area. Open up a new tab in Firefox enter about:config in the address bar and press the enter key. The method described in this guide will work on any desktop operating system that supports Firefox - including Windows XP, Vista, 7, 8, 8.1, Mac OS X, and Linux How To Disable The Firefox Delay While Installing Add-ons or Extensions If you wish to re-enable the delay, change the value back to 1000 (the guide sets it to 0). Using a quick about:config hack, the delay can easily be disabled. The delay is a wonderful security feature for people who don’t really understand how extensions work and are not careful not so wonderful for power-users who are extremely careful and know what they’re doing. If you’re like me, you find it extremely annoying. It makes you take note of what the extension is, where it’s coming from and there’s a slight delay.
If you use Firefox on a regular basis you’ve no doubt seen the warning that comes up when you try to install an add-on or extension.
