Sorry to hear about the issues that you are experiencing. Are you attempting to create an account for the Firefox sync feature? Also, does this prompt display as a popup or website? Please post the URL to the website is possible. Just to let you know, you can use Firefox without registering for a sync account. The sync feature is ideal for people that want to transfer their settings and user data to multiple devices, but it is by no means required to browse the internet using Firefox.

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