That seems to be because that one is the PS1 hack injected into Bleemcast (a PS1 emu for Dreamcast), which does NOT run on Redream or Flycast or any DC emulator.
...But you could simply try the original version from the original creator which can be run on a PS1 emulator (since it is the direct PS1 hack).
This one does work :)
RE: Sonic Invades Crash Bandicoot 2 in New Total Conversion