I'm going to try to explain an issue that scratch my head...
When I open this website for the first time after opening Firefox (v43.0.3), the UI freeze during about 20 seconds and I don't undersand why. For example you can see that the background image appear after almost 20 seconds...
So, I used firebug net panel to try to understand where the problem comes from and I notice that the page load event is very long but I can't see any tasks executing during this event.
here is a screenshot of firebug Net Panel
When I open the website with Chrome it works fine, does someone has ever encounter that kind of problem ?
I hope that makes sense, thank you in advance.
You're making 31 requests (according to my NET panel - FireBug) which add to 323ms (at least in my case). Your background image is loading ~1s after. Maybe if you'd try to reorganize all that sprites you're requesting into less files - but it seems fair as loading time for me.
I once had a problem with Firebug itself. I had to turn it off and\or uninstall to get the page load normally on Firefox.
In my case it was an effect of problem between Firebug and Telerik Kendo JS Library.
Maybe you have a problem similar issue.
Thanks for your answers, indeed it seem's to comes from my firefox configuration or addons/plugins.
I use a Firefox pre-configured by my socity, so I installed a portable firefox to try if it works and the website is loading normaly.
Now I just have to find from whitch config or addons/plugins the problem comes from, thanks again !
Why does Firebug say there is No Javascript on this page when there are clearly loads of JavaScript on the page. I even reloaded the page several time to make sure but it still show the same message.
It never used to do that before, but all of a sudden it misbehaves.
Is it because of some configuration issues or because of something else?
As of Firefox version 50, it seems that Firebug will no longer work as Mozilla are migrating to Firefox Devtools. The tab Tools/Web Developer has a 'debugger' option. See this page for a discussion on the migration. Read all the posts dated 19 November for further information.
It seems to me that the option gives less functionality but Firebug per se is never going to be fixed for Firefox 50 and beyond
EDIT 2017 April
This answer is now outdated and I'm not even testing it anymore because I'm no longer using Firebug (a shame, I loved it years ago in a time it was The tool of trade for web developing).
EDIT 2014 November
The original answer is now more than a year outdated due to firebug evolution.
Thanks to #AmadeusDrZaius to keep it on tracks
Answer for outdated firebug versions
For anyone still with this problem after updating Firebug.
Just click Clear Activation List option inside the Firebug menu.
For those who can't find it, note that "Clear Activation List" shows up in the dropdown from the Firebug icon in the toolbar, but not the Tools > Web Developer > Firebug menu.
I guess due to the bug previous hitting your working page it stays listed as "no activate FB for this site please".
I encountered No Javascript on this page after upgrading Firefox to ver 50.0, with Firebug ver 2.0.18. I tried refreshing Firefox, even completely uninstall Firefox and installed again. Nothing works for me.
A couple of hours later, I downgraded Firefox to 49.0.2, and voila, it works right away. I downloaded the old version here.
I tried everything on this list and nothing worked for me except resetting Firefox like so:
https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-problems
I realize there are already 10 answers to this question, but in my case none of them helped. I'm running Firefox version 39.0 and Firebug version 2.0.11. The only fix is to completely restart Firefox (i.e. not just the tab or instance with the problem).
Perhaps it's due to Firefox's over-usage of memory, or maybe there's a bug in Firebug. I can't speak to that, but what I do know is it didn't work. I killed Firefox, opened the exact same page again with no changes made and now it works. This has happened to me numerous times and a complete restart always fixes it, but that's the only thing that does.
Since Firefox 49.0 and Firebug 2.0.18 the Script panel is broken. This is due to some internal Firefox API changes. And because Firebug is officially discontinued, this unfortunately won't get fixed anymore.
There was also a bug in Firebug 2.0.11 (and below) in combination with Firefox 39.0 causing this problem. This bug is filed as issue 7918.
It happens when the Script panel is enabled and you close Firebug and reopen it.
You can see two related error messages logged to the Browser Console (can be opened via Ctrl+Shift+J or Firebug menu > Developer > Browser Console):
error occurred while processing 'attach: TypeError: docShell is null
Stack: getChildDocShells#resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webbrowser.js:53:7
...
and
onPacket threw an exception: Error: Server did not specify an actor, dropping packet: {"error":"unknownError","message":"error occurred while processing 'attach: TypeError: docShell is null\nStack: getChildDocShells#resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webbrowser.js:53:7
...
Solution:
The only solution until this bug is fixed is to restart Firefox completely.
Similar things have happened to me because I forgot to add the closing tag.
DON'T do this:
<script src="some.url" type="text/javascript">
or
<script src="some.url" type="text/javascript"/>
DO this instead:
<script src="some.url" type="text/javascript"></script>
The same problem just happened to me. I thought that it was a problem in my scripts, but I checked google.com and the problem persisted.
My problem was that I had updated my version of FF and kept the old version of FireBug. When I updated FireBug and everything was solved.
From firefox 49, the fire bug will be built in and it is called fire-bug next. So the fire bug add on won't work properly and no issues will be solved. So you can use firefox inspector. See here for details information
If the problem only shows up on a single page, check that your script folder is referenced from current folder (".") or that's reachable from the server root ("/").
<script src="./scripts/pagescripts.js" type="text/javascript"></script>
may not be the same as
<script src="/scripts/pagescripts.js" type="text/javascript"></script>
As mentioned, sometimes there's a Javascript syntax error that invalidates the whole script. But I have also had this, and simply opening up the page in a new tab or window and refreshing firebug (disable, enable) gets the javascript to show up again.
One time this caught me out was when I published one of my sites and I was checking it out. No Javascript was working, there were no errors in the console and firebug showed no scripts.
It turned out that in that instance, I'd forgotten to allow the site in NoScript - so there really were no scripts being loaded.
Not sure if that's the problem you're facing but it's worth being aware of.
I also got this error when attempting to use Ajax to a different server than the one serving up the page. JavaScript only allows Ajax access to the server that served up the page.
This problem is STILL happening (Aug 2015) with Firefox 39.0.3 and Firebug 2.0.11
For people saying the code is wrong or missing end tags etc. all I did to get all the javascript to reappear in tab was to shut down Firefox and restart it. I didn't change anything. Also that "Clear Activation List" option didn't work (no idea what that means)
I upvoted #Tom_Thomson's answer above, but I am wondering if simply removing and then reinstalling the Firebug add-on might not have accomplished the same thing without losing all the other stuff like bookmarks.
FWIW this problem is still happening in August 2016. I'm using Firebug 2.0.17 with Firefox Dev Edition 50.0a2.
As a workaround, I'm able to use the Developer Tools, though they are not as robust as Firebug (when it's working).
Well Firefox native Inspector is good... I know that you will miss some things, but in general we can survive with it. The good news is... less one addon, FF will be faster :)
I am using kendo in my application and at sometime one of my pages is showing this error in IE and Firefox.But its working fine in Chrome.
A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.
Script: resource://firebug/firebug-service.js:3442
I have searched and found that setting the value dom.max_script_run_time of this will solve the problem.My question is that is it possible to set the value programatically.I mean by using javascript or jquery.If so how.? Any help is much appreciated.
So I just started Working with Sencha Touch 2 and I am already running into some issues. I am currently working through the getting started tutorial but then I'm stuck because after I've made some changes and refresh the page, the loading screen just keeps loading non-stop. This prevents me from moving forward with the tutorial because not matter what I do, it just keeps loading. I tried creating a new project but then run into the same issue again. Can anyone help with this? I would really appreciate it.
Thanks!
I think this is because you must have something in your code that throws an error and therefore prevent the application from executing properly.
Maybe you should try to debug it with Firebug
Hope this helps
I have a situation where I'm inserting javascript generated HTML code into a DIV. One would think this would be a no brainer, but for some reason, once the code is in, the status bar and tab loading graphics start up in both browsers and never stop again. The page continually appears to be loading data, but in reality, there's nothing more to load. Any idea why this may be happening? Solutions? I appreciate any help. Thanks!
Install the Firebug plug-in for Firefox. Open it up and got to the NET tab. That will allow you to see your network activity. Something on the server may be stalling. This will help you find it.