Okay, here's my problem. I wrote some JavaScript for a page, for some reason the page doesn't work in Chrome. The site does what I expect in Opera, Chromium and Firefox. In the Choom devtools there is a kind of error showing in the source tab showing "JavScript is disabled" in a mouse hover popup:
I turned off all chrome's extensions, Javascript in on in the content settings and I cleared all JavaScript exceptions I had, but this didn't seem to change anything. The weird thing (an other one) is that some other sites give the same alert icon in the devtools (including this one) but JavaScript works just fine.
If you perform the exact same functions in the console then, some of, the functions perform just fine.
Does anyone have an idea what I could be because I am out of idea's and it is really annoying that I have to switch browser to test the page (page is 'live' here). Thanks
Have you checked the DevTools settings? You might have accidentally enabled "Disable Javascript"
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This answer is now outdated and I'm not even testing it anymore because I'm no longer using Firebug (a shame, I loved it years ago in a time it was The tool of trade for web developing).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The original answer is now more than a year outdated due to firebug evolution.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Answer for outdated firebug versions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 :)
having a bit of a weird bug. This just started happening in the last 2 days with Chrome only -- the website works fine with Firefox/Opera/IE11 etc. I have no code that messes with the caching of my website to my knowledge.
I am using Google Polymer in order to load shadowDOM custom elements into my DOM. I have a script that still works fine for IE that detects whether the website is IE10 or below, and if it is, doesn't load the script, because if I load the platform.js in IE10 and below my website will just not load at all. Everything was working fine with the script until about 2 days ago when suddenly platform.js is not loading in Chrome, so none of my polymer elements are loading now UNLESS I shift+cmd+refresh my website, clearing the cache.
Was something updated with Chrome / Polymer in the last few days that would have broken this for some reason?
Has anyone encountered this kind of thing where a website will only work when you hard refresh it? I am so confused. Any help would be appreciated. Thanks!
Are you using Polymer 0.5.*? Because if so, you need to load webcomponents.js, not platform.js.
So, I have a heavy page that does a ton of JavaScript and has some huge SVG elements. It's been working great in Webkit/Gecko, but I am now testing in IE and the page doesn't load (well, it loads but most of my JavaScript never seems to run).
First thing I did was drop Firebug Lite into the page to see what's happening, but after I did that, the page loads and functions perfectly in IE! However I don't see the little bug icon to get to the console.
Since I still don't have a console, I'm having trouble figuring out what's happening. Perhaps Firebug defined some variables (console?) that my page needed? Can anyone give some guidance on how to proceed here?
I'll make this an answer since my comment seemed to solve your problem.
If you have uncommented console.log code when running in IE, IE will bark errors at you and fail to properly run the script. Opening a console (IE or Firebug Lite) typically allows the code to run, however you obviously cannot count on your visitors doing this, therefore it's always best to remove or comment out all console.log() calls when releasing production code.
Okay I think I figured this out. console is only defined in IE8+ IF the developer console has been opened and the page refreshed. So including Firebug Lite probably made my page work by itself defining console.
So I'll just have to comment out my console.log statements when the page is public.
After updating Google Chrome browser to the latest 15.0.874.106 version (under Windows 7), my site is experiencing some weird flickering bug.
The text shadows are displaying completely wrong, the text itself is fuzzy and unclear, some parts of code don't work anymore (e.g. right floating, fixed menu)... etc.
For a couple of seconds the site is displayed fine, then it flickers all of the sudden (while still loading) and then the rendering gets messed up. (I think it has maybe some problems with loading of Google Maps v3)
The funny thing is that the old version of Chrome (before updating, on my other computer) is still displaying the site without any problems, and there haven't been any changes in the code in the meanwhile.
In other browsers (as i said, even in the old chrome) everything is OK. Firebug and Chrome's code inspector (CTRL+SHIFT+J) don't show any errors in the code. I have been doing some digging on the Internet and here as well, and I havent't found anything useful.
You can check it out by yourself by clicking here
Thanks in advance.
I have done same settings changes as mentioned above post and now, that weird flicker got stopped, below are the details....
Open Chrome Browser
Click on Settings menu option
Click on Advance setting link in Settings page
Un-Check "Use Hardware acceleration when available" checkbox
Restart you chrome browser
Happy Browsing....... :)
Also make sure to disable not only accelerated-compositing, but also accelerated-2d-canvas.
This is how I start google-chrome on Linux:
/opt/google/chrome/google-chrome %U --user-data-dir=/root --disable-accelerated-compositing --disable-accelerated-2d-canvas
On Windows, you might want to omit
--user-data-dir=/root
Josip Filipović apology where to do that (in Win7 by entering -disable-accelerated-compositing in properties > target field) that part disables hardware acceleration.