Hi, yes I'm the creator of Degausser (from the old DX Degausser to the more modern Degausser for bbp, and also degausser3ds), though I've been away from the scene for a while, so it's exciting to see things are still happening.
I did have a look...
what error is DX Degausser giving you? it's been well over a decade since I last worked on it, but I think people have around come up with all sorts of workarounds for the most common issues. they'll be spread around gbatemp somewhere
Here's my take on a bbp2midi converter while I upgrade degausser to v3.0:
https://adib.fourplusfive.com/bbp2midi/v1.0/
It's compatible with the BBP soundfont2 a few posts earlier. And can also load bdx files.