Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Hilfe durchsuchen

Vorsicht vor Support-Betrug: Wir fordern Sie niemals auf, eine Telefonnummer anzurufen, eine SMS an eine Telefonnummer zu senden oder persönliche Daten preiszugeben. Bitte melden Sie verdächtige Aktivitäten über die Funktion „Missbrauch melden“.

Learn More

When starting Firefox 4 I get an error message. After clicking OK it nevertheless runs. How can I get rid off the error message.

more options

When starting up Firefox 4 I get an error message. After clicking OK it nevertheless runs. How can I get rid off the error message?

The error message is: what happened: Type Error: Components. classes ['@mozilla.org/extensions/manager;1'] is undefined.

It appears all the time already from the beginning after installing Firefox 4.

When starting up Firefox 4 I get an error message. After clicking OK it nevertheless runs. How can I get rid off the error message? The error message is: what happened: Type Error: Components. classes ['@mozilla.org/extensions/manager;1'] is undefined. It appears all the time already from the beginning after installing Firefox 4.

Alle Antworten (2)

more options

That indicates that you are using an add-on that is not compatible with Firefox 4. For details of how to troubleshoot that see https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

more options

Thanks a lot. The Ask toolbar created this problem. Another problem is: When searching on the web via Google, normally it is possible to type a few letters and then look what appears and then click on the wanted word(s). A number of word(s) ineed do appear, however it is not possible to select any of them as ws possible as mentioned in olders versions.