Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

TypeError, Components.classes['@mozilla.org/network/urichecker;1'] is undefined

  • 2 replies
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

chapochkin
chapochkin
more options

After the last update (to 45.0.1) I am constantly getting this error:

[JavaScript Application] Error on switching in renew: TypeError, Components.classes['@mozilla.org/network/urichecker;1'] is undefined

It doesn't prevent browser to continue what it has to do BUT still not nice to see it....

Any recommendations ?

Thanks

After the last update (to 45.0.1) I am constantly getting this error: [JavaScript Application] Error on switching in renew: TypeError, Components.classes['@mozilla.org/network/urichecker;1'] is undefined It doesn't prevent browser to continue what it has to do BUT still not nice to see it.... Any recommendations ? Thanks

All Replies (2)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 10 Contributor
more options

Hmm, I don't know that one. I can think of two possibilities:

(1) Perhaps Firefox 45 is not fully compatible with one of your extensions. As a test, could you run in Firefox's Safe Mode for a while? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

  • "3-bar" menu button > "?" button > Restart with Add-ons Disabled
  • Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement? (More info: Diagnose Firefox issues using Troubleshoot Mode)

(2) Perhaps Firefox's program files were corrupted during the last update. For that, we usually recommend:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 45.0.1 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.) For maximum plugin compatibility, choose the 32-bit version.

(B) Exit out of Firefox (if applicable).

(C) Rename the program folder as follows:

(32-bit Firefox on 64-bit Windows) 

C:\Program Files (x86)\Mozilla Firefox

to 

C:\Program Files (x86)\OldFirefox

(Other systems) 

C:\Program Files\Mozilla Firefox

to 

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in step (A). It should automatically connect to your existing settings.

Does the message stop appearing?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders, but to avoid introducing problems, please don't just copy everything over:

  • \OldFirefox\Plugins
  • \OldFirefox\browser\plugins
cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Can you list your extensions?