[mattjackson]

If you are running the UD02 firmware on my site, it can be flashed to UD04 1.14 - Any UD02 should work so long as it runs the firmware on my site.

Only reason it has to be the version on my site (and I mean version 1.00 not "my" specific file) is that my flasher only certifies the UD02 1.00 to UD04 1.14 - Only

Do not then flash to other UD04 versions or try to cross flash to say a UD03. You own a UD02, that needs to be the base firmware always.

I would suggest you always flash back to UD02 1.00 then up again if more cross flashes come in future (not sure why they will this is enough lol). My flasher has to know you were originally on a UD02 and now going to a UD04 to make the modifications to the UD04 thats needed to be flashed onto a UD02. You wont break anything you just may not get the right results if you tell my flasher the current is UD04 and you try to go to something else.
As such you will notice there is no UD04 > UD02 listed on website. A UD04 can not become a UD02 (I could but why). If you want back to UD02 download 1.00 from its page.