This came up recently. They've changed the numbering system. But you should be OK.
If you go into "Register the product" and you see a number, you are probably fine.
This looks like hangover from the bad old days of writing the user interface. More modern software tells you that it is registered to you, or at least registered, when you go >>Help>>About.
X1 should catch up with what has happened on that front over the past five years or so.