Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

You can also check these prefs on the about:config page.

• http://kb.mozillazine.org/view_source.editor.external
• http://kb.mozillazine.org/view_source.editor.path

same here, no view source feature, no view image info neither.

As requested, I tried starting in safe mode, with addons disabled.

I still have the same problem. Nothing appears to happen when I choose Page Source form the View menu. Also, typing command-U does nothing.

I'm using FF 4.0 for Mac OS 10.6.6.

Also, as suggested, I checked my preferences:

view_source.editor.external is set to false (i.e. use internal view source) view_source.editor.path is empty

The issue here - but it seems to be an issue with opening new windows, not just the view source feature. e.g. Ctrl-N doesn't work either. However I can see the list of windows that are open in the Window toolbar, just can't actually see them.

I tried starting Firefox 4.0 in Safe Mode, and I still could not view the page source.

view_source.editor.external -- Status = default | Type = boolean | Value = false view_source.editor.path -- Status = default | Type = string | Value is blank

Neither of these fixed my problem. Again, I'm using Firefox 4.0 on Mac OS X 10.6.7.

This is really kind of an annoying problem, as I'm a Web developer and use the "View Page Source" feature quite often. Granted I can still use Firebug, but sometimes I just want to see the full page of source code without all the added features.

So I just made a discovery. I have two screens; when Firefox is on the main screen, I can right-click and view the pages' source code. However, when I'm on the secondary monitor, I can right-click and select "View page source," but nothing happens. Weird.

Does this sound like a Firefox issue, or a Mac OS X issue?

@mkimitch - Thanks for that, it seems to be my problem on my Mac too. Main screen it operates fine. (nothing happens when trying to open a link in a new window either)

Other programs seem to work (old firefox, safari, chrome etc) so my guess it's a firefox 4 issue.

mkimitch, occurs the same here.

I've noticed too that only in main display the "cmd+u" gives me the source code. In second display, nothing happens.

FYI on my MBP this problem occurs only if the secondary monitor is to the left of the primary. If the monitor is to the right the source screen shows up on the primary monitor.

A workaround to this problem is to set your view_source.editor.path to an external editor. I'm using TextMate here and it works even on the secondary monitor.

Here are my settings:

view_source.editor.external = true

view_source.editor.path = /Applications/TextMate.app/Contents/Resources/mate

We use MBPs at work, and I was having the same problem, very inconvenient since I work as a web developer and administrator. I fixed this, as per mkimitch's suggestion about 2 screens, by modifying the screen arrangement properties. Basically, I went from this arrangement

http://i.imgur.com/law6z.png

to this arrangement

http://i.imgur.com/hEqbA.png

Noticed the SLIGHT adjustment in the secondary screen downwards to be flush with the top of the primary screen. View source now works perfectly. Hope this helps someone.

shmeeps solved it!

You rock shmeeps. This still isn't fixed in version 8.0

The arrangement of the screens is not a good solution in my case (although it works perfectly), so I opted to install this plugin, View Source Chart: https://addons.mozilla.org/en-US/firefox/addon/view-source-chart/?src=search.

It solves the problem in a colateral way by just opening the source in a Tab instead of a new window. Plus you get a very nice structured code view, so highly recommended anyway.