I recently bought a spiffy top-of-the-range washer/drier to replaced my 15-year-old one. I did my research; knew it was wifi-enabled, but could be used without

I recently bought a spiffy top-of-the-range washer/drier to replaced my 15-year-old one. I did my research; knew it was wifi-enabled, but could be used without the app or an internet connection. So that's what I did at first. Then I tried to configure it to use the manufacturer's app, so that I could check power consumption and consumables remotely. The app refused to let me use it without registering an account with the manufacturer. As part of account setup it demanded my street address, then when I entered it it crashed. (Hint: there's a slash in my street address. Yes, this is my official address as per the Post Office. Yes, Scottish street addresses are odd.) Nevertheless: the app crashed. It handed me a long alphanumeric error code returned by the server ... then thereafter refused to let me abort the registration process or edit the address, instead delivering a variety of new and exciting long alphanumeric server-side error codes every time I tried it. I was not impressed. (I'm guessing it passed the address through to a SQL or other DBMS that didn't properly escape or filter the raw input ... and got part-way through initializing some records that were part of the account but was unable to recover from the dodgy input data, leaving me in limbo.) TLDR: my washing machine disapproves of my street address. (Luckily it works just fine without knowing it. So there's that.)