Imagine you're a user filling in a registration form on a website. The form has about 20 required fields, so it's not a small form. Because the entire form uses inline validation, you're confident you filled in the entire form correctly. However, when clicking "submit", a network connection or unexpected server problem occurs and the registration cannot complete. Result: you'll have to register at a later time, when this problem is fixed.
Now, let's say the program automatically takes you back to the registration form, with all previous entered fields filled in automatically. You try again, but you get the same problem. You will actually have to wait one hour or more until the problem is really fixed.
What could be a possible mechanism to prevent users from having to type everything in again? Because the server was down for an unspecified time, the data could not be stored on the server (otherwise the registration would have succeeded). But I cannot rely on the use keeping the website open all the time.
Perhaps I could test a stable server connection right before the user starts filling in the registration form, because it is very likely the connection will still be up a small time later?