We are updating the extension, therefore a popup might appear (it will only happen once per browser/device), but you can simply close it and continue browsing. We don't track who has previously paid unless your extension is already upgraded to Adblock Plus Premium (and in that case we won't show you the update page at all). If you are encountering the payment page every time you open your browser, please reach out to us via sour support form: https://help.adblockplus.org/hc/en-us/requests/new.