Wops, sorry if my bad english misleaded you to try change the name of the file, that's not a good idea at all.
What I mean to say is that this file can be a bad or wrong file, and the genuine file for the update may have another name that correspond to the keyboard it's made for.

Always be very careful when update firmware, because if anything goes wrong, the keyboard might stop work.

I'll keep my eyes open and look for any solution. But as we know there is hard to find any support and update for Technics nowadays.