I have an important question regarding M.U.G.E.N. versions

[Roxeles]

mugen 1.1 has compatibilities with mugen 1.0, and sometimes Winmugen. It only depends on certain coding for some chars, but I've only seen that with winmugen chars (like insanely overpowered/ear-blasting/eye-melting cheapies) but those are rarely created nowadays, so you should be fine

Thank you very much