Unfortunately, like most games of telephone, things get a little.... messy... along the way. What starts at one end as a useful message often comes out garbled. For example, "This account is disabled" comes across as "Unknown error". (thanks!)
Now, most of the time, we can figure out what the error means in the end. Usually, we end up calling the originating system and saying, "what do you see?" We've built ourselves an informal table of likely translations.
There's one error, though, that we can't figure out:
Error 75: "Thank you for using
That's the most cheerful error message I think I've ever seen. I'm not sure it's even an error! We haven't really figured out what to do with it, but boy did we at last get a laugh out of it.