Unresponsive Script Warning

From MozillaZine Knowledge Base

When JavaScript code runs for longer than a predefined amount of time, Firefox will display a dialog that says Warning: Unresponsive Script. This time is given by the settings dom.max_script_run_time and dom.max_chrome_script_run_time. Increasing the values of those settings will cause the warning to appear less often, but will defeat the purpose: to inform you of a problem with an extension or web site so you can stop the runaway script.

Complete Error Message: “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.”

Sometimes you may be able to identify the extension:

"Script: chrome://fastdial/content/storage.js:71"

1 Finding the source of the problem
2 Extensions
- 2.1 Disabling extensions or rebuilding a new profile
3 Websites
- 3.1 Updating Java
4 Webroot Spy Sweeper
5 Finding similar problems
6 See also
7 External

[edit]

Finding the source of the problem

To determine what script is running too long, click the Stop Script button on the warning dialog, then go to Tools | Error Console. The most recent errors in the Error Console should identify the script causing the problem.

[edit]

Extensions

If you get the Unresponsive Script Warning on many different web pages, the problem is most likely a recently installed extension.[1] You can try uninstalling extensions to fix the problem, or try creating a new profile.

Some extensions reported having Unresponsive Script Errors

A9 Toolbar [2]
Adobe Reader (update Adobe Reader) [3]
AutoAdd (use QuickAdd instead) [4]
Extended Cookie Manager [5]
Fast Dial, delete the Fast Dial folder and reinstall [6]
Febe [7]
FoxyProxy when using GMail [8]
Gladder conflicts with UpdateScanner 3.0.4. When you open a page from UpdateScanner Firefox hangs for awhile[9]
Lazarus: Form Recovery, fixed in 3.0 see author's homepage if not yet at add-ons.
[Beta] Phoogle (Google) Map Mod 0.4.0 [10]
Media Player Connectivity [11]
MobWars scripts, try reseting your boss database. [12]
McAfee Spamkiller [13]
Unshorten v1.3 [14]
YouSendIt [15]

[edit]

Disabling extensions or rebuilding a new profile

There are several techniques that can be used to identify bad extensions by disabling or rebuilding.

Disabling half of the extensions in a bad group of extensions, until reduced to one extension that fails and would be left disabled waiting for an update or uninstalled. Don't immediately reinstall all the other disabled extensions, use a little care and just restore half of the others, if good then restore the other half.
Rebuilding a new Profile: [16] -- If the new Profile works correctly, then you can migrate specific files: [17] and reinstall extensions.

[edit]

Websites

If you get the Unresponsive Script Warning on a specific web page, it could be a problem with the JavaScript on the web page. You may want to contact the webmaster of the site to inform them of the problem, or you may wish to file a Tech Evangelism bug report. Steffen Rusitschka suggests using setTimeout on web pages that need to execute JavaScript for long periods of time.

[edit]

Updating Java

Updating Java seems to have helped the following pages. Note Java is not the same as JavaScript.

iCloud.com with Firefox 8 and "Find My Phone" [18] (Updated to Java Version 6 Update 30)

[edit]

Webroot Spy Sweeper

The Webroot Spy Sweeper application can cause an Unresponsive Script Warning on certain web pages. Try disabling or uninstalling the application, then clear cookies for the related websites. [19]

[edit]