It is official update from Onyx.
The "problem" is that some resellers add some extra SW and probably because of licence reasons, they do not allow instalation of common firmware. It makes sort of sense, because additional SW would be lost. So, they must make their own version of firmware.
The update also does not work, if you modify the name of firmware so that it does not end, as it ends (by numbers). You may change the name by prefix, but not by suffix. (I encoutered that problem, as I added version suffix to the name...)