I’ve just been switched from Freestyle Libre 2 to 3, and (at least in the UK) these need to be requested directly from Abbott instead of via regular NHS prescriptions that go to a pharmacist. To do this, you have to use their patient portal, so you need a password and need to go through their password reset process. The listed requirements are a minimum of eight characters, five lower-case letters, one upper-case letter, a number and a symbol, but there’s either also a maximum number of characters (I typically use way more than eight) or a restriction on which symbols are permitted. If you don’t meet the hidden extra requirements, you’ll get a 404 during the password reset process (which isn’t even the right error code for this kind of thing).

It took a lot of tries before my password manager came up with something the website was happy with, and no one seems to have written anything on the searchable parts of the internet about it, so I wasn’t sure it was going to work and thought I might just have hit outages on both days I tried, so I’m writing this here in the hope that the next time someone sees the same error, this will show up in a search, and they know they need to change the password they’re trying to set.

I’m not going to go into what eventually worked and which characters were allowed, as obviously that’d give away more information about the password I ended up with than I’m comfortable disclosing, so sorry for not specifying precisely what the real requirements are.