Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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
Denc nañu waxtaan wii. Yónneel yeneen laaj soo soxlaa ndimbal.
Solved Yiñ denc

I can't open FF and get message: Error: a is undefined

Firefox
JoanBrevard replied
JoanBrevard
JoanBrevard

FF won't open, even if in safe mode. Under FF, I get an error box with the message "Error: a is undefined" the error info is "Source File: http://www.google.com/extern_js/f/CgJlbhICdXMrMFo4ACwrMA44ACwrMBc4ACwrMDw4ACwrMFE4ACwrMFk4ACwrMAo4AEBdmgICcHMsKzAWOAAsKzAZOAAsKzAlOAAsKzAqOAAsKzArOAAsKzA1OAAsKzBAOAAsKzBBOAAsKzBNOAAsKzBOOAAsKzBTOAAsKzBUOAAsKzBfOAAsKzBjOAAsKzBpOAAsKzB0OAAsKzAdOAAsKzBcOAAsKzAYOAAsgAI8kAI2/BFKlF3L_Vtk.js Line: 333" What is solution?

FF won't open, even if in safe mode. Under FF, I get an error box with the message "Error: a is undefined" the error info is "Source File: http://www.google.com/extern_js/f/CgJlbhICdXMrMFo4ACwrMA44ACwrMBc4ACwrMDw4ACwrMFE4ACwrMFk4ACwrMAo4AEBdmgICcHMsKzAWOAAsKzAZOAAsKzAlOAAsKzAqOAAsKzArOAAsKzA1OAAsKzBAOAAsKzBBOAAsKzBNOAAsKzBOOAAsKzBTOAAsKzBUOAAsKzBfOAAsKzBjOAAsKzBpOAAsKzB0OAAsKzAdOAAsKzBcOAAsKzAYOAAsgAI8kAI2/BFKlF3L_Vtk.js Line: 333" What is solution?

All Replies (2)

cor-el
cor-el
  • Saytukat

Saafara yiñ Tànn

  • "Clear the Cache": Firefox > Preferences > Advanced > Network > Offline Storage (Cache): "Clear Now"
  • "Remove the Cookies" from sites causing problems: Firefox > Preferences > Privacy > Cookies: "Show Cookies"

Start Firefox in Use Troubleshoot Mode in Firefox to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Appearance/Themes).

  • Don't make any changes on the Safe mode start window.

See:

JoanBrevard
JoanBrevard Ki laajte

Clearing the Cache as described worked. Thank you very much.