To be honest, I also have the same issue by not having the music playing at the credits due to the music file being way too strong or something else I don't know about... I also want this issue to be fixed because I don't want to have a credits every time I go there and there's nothing to be heard from the game itself.
Try to install LunaLUA+SDL into your SMBX [Don't worry, it's simple and easy, goto "Full install" and check "Complete standalone game"], mayby you have problem with installed codecs. SDL Mixer uses built-in decoders a you must have everything working.
Wohlstand wrote:Try to install LunaLUA+SDL into your SMBX [Don't worry, it's simple and easy, goto "Full install" and check "Complete standalone game"], mayby you have problem with installed codecs. SDL Mixer uses built-in decoders a you must have everything working.
Reinstalling was a temp fix at best, tried this instead. Worked. No idea why this isn't just the default game.