May be related to this issue. Seems that it's a known bug that has been assigned.

Did you try to disable your extensions as a test to see if that makes the Debugger work?

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

• https://developer.mozilla.org/en/Tools/Debugger

Thanks, yes as I noted in my OP, I tried disabling all extensions.

Also tried the "Reset Firefox" button.

Neither worked. I'll give "safe mode" a try.

EDIT: I'm now in "safe mode", and the issue persists.

The bug report mentions some specific extensions that cause scripts not to get loaded or otherwise interfere.

Your system details list doesn't show any of the extensions mentioned in the bug report, so in your case it might be something different.

Do you see any errors in the Web Developer > Error Console (Ctrl+Shift+J) related to this?

You can hide the usual CSS errors that show up.

Ah yes. I had the wrong console open at first. I had Ctrl+Shift+K.

In the Error console, I get:

09/11/2012 04:50:36 PM

[Exception... "Component returned failure code: 0x80470002 (NS_BASE_STREAM_CLOSED) [nsIOutputStream.write]" nsresult: "0x80470002 (NS_BASE_STREAM_CLOSED)" location: "JS frame :: chrome://global/content/devtools/dbg-transport.js :: DT_onOutputStreamReady :: line 94" data: no]

chrome://global/content/devtools/dbg-transport.js Line: 94

It looks that Firefox is trying to set up for remote debugging.

Do you have any of the devtools.debugger.* prefs set to a user set (i.e. not default) value?

• devtools.debugger.remote-enabled

• http://kb.mozillazine.org/about:config

I don't believe I have changed any such settings. How would one check that?

I previously had Firebug and YSlow installed. Could it be that one of those would have changed a setting?

I'm checking right now.

devtools.debugger.remote-enabled is false

I'll look for other remote settings.

All the devtools.debugger settings have the default setting applied.

Still not working.

My latest attempt was to do the following...

• sudo apt-get remove firefox
• mv ~/.mozilla ~/.mozilla_old
• whereis firefox (and rm -r the found directories)
• whereis mozilla (and rm -r the found directories)
• sudo apt-get install firefox

I would think this would give me an entirely clean installation, but it didn't solve the issue.

Did you try to install Firefox from the Mozilla server instead of via the repositories of your Linux distribution?

You can find the latest Firefox release in all languages and for all Operating Systems here:

• Firefox 15.0.x: http://www.mozilla.org/en-US/firefox/all.html

• http://kb.mozillazine.org/Installing_Firefox#Linux

Good idea. I'll give that a try in the morning. Strange that my other Linux installation works.

Unfortunately, the non-repo Firefox behaved the same way.

Since my MacBook Pro Linux installation works, I have a feeling there must either be some software or driver on this machine causing the issue.

I'm going to install Linux in VirtualBox on this same machine, and see if I experience the same problem.

Thanks for your help thus far!

I can't replicate the issue in another installation.

I've a feeling there's just something deep in the bowels of my Linux install that is fubar'd. I may just need to clean install my system.

I have exactly the same issue on my Windows 7 machine with Firefox 16.0.1. Any leads on how to fix it?

Unfortunately no. I haven't been able to resolve this, and I can't replicate it on another machine, so I've given up.

If you come across a solution, please let me know!

I'm having the same problem in Firefox 16.0.2 on Ubuntu 12.04. Whenever I try to start the debugger the following error appears in the error console.

Timestamp: 11/16/2012 08:39:20 PM Error: [Exception... "Component returned failure code: 0x80470002 (NS_BASE_STREAM_CLOSED) [nsIOutputStream.write]" nsresult: "0x80470002 (NS_BASE_STREAM_CLOSED)" location: "JS frame :: chrome://global/content/devtools/dbg-transport.js :: DT_onOutputStreamReady :: line 94" data: no] Source File: chrome://global/content/devtools/dbg-transport.js Line: 94

Issue appears to be fixed in Firefox 17.