Just wanted to get the word out somewhere, since I only found this on a facebook post after a bunch of digging:
If you’re trying to update a Yamaha QY100 sequencer to latest firmware found here, you have to use XGWorks, which can be found on this page.

I tried using Sysex Librarian and got a ‘range err’ at line 1177
I tried using Bome SendSX and got a ‘dram c.sum err’ also at line 1177
(Line 1177 is shorter than the others for some reason)

• Install XGWorks – seems to install fine on Win10-64
• Extract the firmware zipfile and follow the instructions in the readme for putting the sequencer into firmware mode
• Launch XGWorks, and open QY100_v137.mid
• Make sure the correct midi interface is selected, and press play.

The whole thing takes about 15 – 20 minutes. Initially you’ll see it erase the current firmware, then it’ll say OK for a bit, then it’ll show an Address = xxxxxx that will start counting up. It will periodically stop, say OK, then start counting up again, and eventually you’ll see a message saying it succeeded.
If you use any other sysex utility, it will just keep counting up until it throws one of the above errors at line 1177 (the address will vary, but it will always be at that line in the sysex file).

Just in case, here are local links to both resources (I like to link to the original sources whenever possible, but also like to have a back-up)
QY-100 Firmware 1.37
XGWorks