Hello Robert, do you have Ghostery add-on installed ? If yes, unblock the AdobeTagManager in Ghostery and check it again.

thank you

Never heard of "Ghostery". The only add-ons I have are: Google Translator for Firefox Im Translator Kaspersky Protection

Kindly advise. Thanks and regards Robert Meier

Please check if the issue persist in firefox safe mode.

thank you

Have gone thru Table of Contents No. 1 to 4 and 6 in the Troubleshoot and diagnose Firefox section but nothing works. In the meantime I have lost the 3 add-ons. How do I get those back. Kindly advise. Thanks Robert Meier

RMeier said

In the meantime I have lost the 3 add-ons.

To exit safe mode, click the 3-bar menu on your right-up, and choose the exit firefox button (in the pop-up menu down in your right).

In safe mode also you have the same massage "Unfortunately your browser doesn't support My O2. Upgrade to the latest browser version" ?

I also have the same message from O2 in safe mode. In future I will just copy the link into Microsoft Edge which works.

Thanks for your efforts.

Regards Robert Meier

Do you already get this message on the sign in page?

• https://accounts.o2.co.uk/signin

Clear the cache and remove the cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Clear the cache":

• Firefox/Options/Preferences -> Advanced -> Network -> Cached Web Content: "Clear Now"

"Remove the cookies" from websites that cause problems.

• Firefox/Options/Preferences -> Privacy -> "Use custom settings for history" -> Cookies: "Show Cookies"