Do NOT, repeat do NOT under any circumstances 'upgrade' to a Jagex Account.
If you do you will be locked out from logging into Runescape.
You will spend hours going around and around in circles on the Runescape / Jagex websites and end up with nothing but frustration.
You will NOT be able to download a new Runescape Launcher installer in an attempt to fix the login issues because Jagex have totally managed to break even that simple task. Their web servers are, as at 5th June 2023, completely broken.
05-Jun-2023 17:07:44