DOM Inspector problem

DOM InspectorI’ve been using Mozilla’s DOM Inspector for a long time now and I’ve come to depend on it as my rapid problem solver. Need to instantly figure out the structure of a page I’ve never worked on? No problem. See all style rules applying to an element then look up their line numbers in the style sheet? Easy. CSS specificity issue? Non-issue. This tool definitely makes my life easier. But I use it mainly for CSS, and now the CSS component seems to be broken for me.

A problem I’ve had a few times before and am currently experiencing is when you launch the DOM Inspector and inspect a page, switching to CSS Style Rules in the right-hand pane shows nothing! The panes just appear empty. I had this same issue at some stage around the release of Firefox 1.5, but one of the minor updates seemed to have fixed it. Now that I have installed the excellent Firefox 2 (for Windows), the problem has returned. It happened on my machine at work since installing FF 2, and now it’s happened on my home machine since upgrading FF – a mistake on my part in hindsight, seeing I’m trying to finish my new site for launch by Wednesday evening.

DOM Inspector

Here’s the Bugzilla record of the problem, (and it looks like I’m not alone).

Is anyone out there getting this problem? Better still, anyone got a fix? I haven’t found any answers to this problem and it’s causing me grief. I hope the Firefox team fix it soon!

Update 15/11/2006

OK I have found a temporary workaround of sorts. I can’t guarantee this will work for everyone having this problem, but when I had Firefox 1.5, my DOM Inspector still worked, so… I installed 1.5 again, in a different directory (something like C:\Program Files\Mozilla Firefox 1.5) making sure to select Custom install and confirming Developer Tools was selected. So now, I still use Firefox 2 (with the broken Inspector) for everyday use, but when I really want to use the DOM Inspector I switch back to 1.5 and the DOM Inspector works just fine like before! If your FF 1.5 Inspector was broken, well I don’t know how to help you there, except to suggest maybe try reinstalling Firefox…

I don’t know why I didn’t try this sooner. Well actually I do, I’m packing my life up getting ready to travel and live overseas, but anyway…

And by the way, you can’t run Firefox 2 AND 1.5 at the same time… if FF 2 is running and you fire up Firefox 1.5, it will just run another instance of 2.


  1. Yeah totally, I get the exact same problem now, it also effects the Style tab within the Inspector panel, within the now famous Firebug extension… that too is blank :’(

  2. I get to say “Me too!”. Very frustrating, as the CSS style rules is my most used part of the DOM inspector. I’m glad I found your page so I knew I wasn’t alone.

  3. I get that problem too – I just did a google search to see if there were any fixes out there and I came across your page… No luck in finding a solution yet…

  4. Just adding my name to the list… Yup, its a Firefox 2 issue, alright. And a damn annoying one at that!..

  5. Ditto here. I kind of think it started when I upgraded from 1.5 to beta 2 in September…

  6. Thanks for stopping in everyone. I just updated the post with a workaround that works for me, I hope it helps you guys. In the end though, the FF guys need to come up with something to fix it properly.

  7. I’m glad I found this page. I thought that some other extension had been screwing up DOM Inspector.

  8. After noticing that DOM Inspector correctly worked on another machine, I uninstalled Firefox and all other variants of Mozilla and reinstalled Firefox 2. That fixed the problem.

  9. I had this problem as well, and I think it is because the system was upgraded from an older version where the files were in a different location. Firefox is probably picking up old versions of some files.

    I ran a command prompt in “\Program Files\Mozilla Firefox” and did “dir inspector*.* /s”. This found a bunch of files beginning with “inspector” in subdirectories chrome, components, defaults\prefs extensions\, and res. On a system where the DOM inspector was working properly the dir command only found files in extensions\

    Deleting all of the files matching “inspector*.*” except those under extensions should fix the problem. (I’m not absolutely certain it does because what I actually did was to delete all files beginning with inspector and then reinstalled Firefox on top of the existing installation).