Regarding to the xgmtools, please write an email to Stef who is the creator of the tool: stephane.d [ A T ] outlook [ D O T ] C O M

welcome here!

You seem to have quite much experiences with old computers, that's cool!

Are you still making some 1-bit music for your TK90X? Anyway, if you're still interested, we have an other forum dedicated to 1-bit music, you can see the amazing new 1-bit engines which are still made today, for example: http://randomflux.info/1bit/viewtopic.php?id=99

About your vgm problem, I don't really know because I've never used xgmtools, but can't you just check your music and try to remove the warning? It looks like it it's trying to reach too low or too high keys then maybe it's the reason for crashing? Alternatively have you tried to convert a simpler music to check if your game is not crashing this way too (the problem could be only with the converter?).
You can also try to convert to rom instead of vgm (deflemask can export to .gen format), then maybe it's possible to extract the music from there and put it in your game? (the .gen roms I've made this way can replay well on my megadrive, using an everdrive cart)

  I've done music from my 11 years with the "Wham! The music box" program, with my first home computer, a "TK90X" (ZX Spectrum Brazilian Clone) . In the 1994 i catch to the "Fast Tracker II". In 2000 ModPlug Tracker and Guitar Pro. 2002 i worked with Cakewalk Sonar 4, Giga Studio, EWQLSO Native Instruments, EZ Drummer, "Mixing and Mastering with waves" and so ... have returned to the roots, using C64 Retroskoi , My own tracker for the ZX Spectrum + 3e (made with ZXBoriel compiled BASIC), ProTracker for the AMIGA500 ... and DefleMask, to make music for SEGA GENESIS.
  Well, I tried to convert VGM to XGC with xgmtool, songs maked With DefleMask, to finaly, run this with Basiega compiled file, but... jumps me a WARNING... I think is the problem that makes MUSIC & game freeze in SEGA GENESIS with Everdrive or any emulator.

I have already tried to import almost totally empty projects, with a single pattern, and with a single instrument, I jump the same mistake.

"Waning: more then 6 key command key on or off in a single frame!"

i have no idea what is this

a pic:

Anybody can give me a hand on this?
The game will be finished as soon as I get a solution, hehehe

well, eternally grateful.
Regards!