One page on a client's site causes Chrome to hang unresponsively for 15 seconds or so. On macOS, the browser locks up completely and the spinning wheel appears.
There are no issues whatsoever in Safari or Firefox. I have no idea why this is happening, and DevTools doesn't seem to give any clues as to what's causing it.
Here's a screenshot of the timeline — note the flurry of activity in the final second, when the browser becomes responsive after seemingly doing "nothing" in the latter half:
Some comments on the timeline above:
At ~12,500ms the page looks ready. In any other browser, it is ready for interaction at this point. You can see the final green chunk in the timeline finishes around here.
Chrome completely locks up between 12,500ms and 28,500ms.
I initially assumed the problem was with one of the 3rd-party/analytics scripts, as you can see the timeline shows activity from these right in the final second (> 28,000ms). I tried switching every one of these off, but exactly the same thing happens.
This is a particularly large page, as it lists several thousand records in a JS datatable. I appreciate performance can be improved, but I don't believe that's the root cause. The page/plugin has been working absolutely fine for several years.
What can I try next? Thanks! 🙏
This turned out to be a bug in Google Chrome v107. Updating to v108 fixed the issue immediately.
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This answer is now outdated and I'm not even testing it anymore because I'm no longer using Firebug (a shame, I loved it years ago in a time it was The tool of trade for web developing).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The original answer is now more than a year outdated due to firebug evolution.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Answer for outdated firebug versions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 :)
An alert/prompt called from chrome extension background pake is shown off the screen (or partially in top left screen). This bug has been fixed in canary build by now, see
http://code.google.com/p/chromium/issues/detail?id=113899 , but I need to get it working as soon as possible. Do you have any ideas how to work this around using javascript?
Thanks in advance.
PS: I'm talking about this extension: https://chrome.google.com/webstore/detail/jfiakckbklmccchjegnnojbalafebakb
You can't position the alert or prompt dialogs in browsers. You have to wait for the bug fix to propagate to the stable branch.
An alternative option is to inject an HTML lightbox into the current tab but that would be a lot of additional work.
One way to go is to further investigate the canary source code, found at the Chromium project on Google Code.
The issue is reported on the Chromium issues page, and the fix seem to be found at this revision on the Chromium sources.
You can check out the diff and compile a workaround based on their solution.
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.
LINK TO THE PAGE NO LONGER ACTIVE, THANKS FOR VISITING, Rene
Hi,
I have a page here and I can't understand why is IE8 rendering this page so slowly.
Originally I thought it was the scrolling text at the top but it's not as I commented it out with no progress. So then I profiled with developer tools for IE8 and it shows a lot of anonymous functions running which I suspect come from jquery (which is not loaded by me directly) but the developer tools cannot show me the source code for those functions. So I can't pin down the problem on what are those phantom functions running from or why as I have no experience with jquery. I noticed that those functions do not run in FF when I profiled it with FireBug so maybe something is running for IE but not for FF ? I am a bit lost.
Any help/suggestions is greatly appreciated!
Thanks so much,
Rene
I was able to see the process jumping between 79MB and 65MB off and on. It may be an issue of memory not being freed up or perhaps an inefficient background operation that is hanging everything up.
I would go with meder5's advice. I would comment any and all unnecessary code and start with the bare minimum and track performance till you find the bottleneck as you add pieces back in.
Hi I also tested in Chrome 8. Frankly, the page is neither fast in IE nor FF nor Chrome. But its relatively faster in FF and Chrome much than IE. I suppose it has something to do with the different mechanisms of FF/Chrome and IE use handling contents.
By the way, I appreciate that you guys can do very nice animation with javascript&jquery,