If change in songdefs entrysong clipPath to another, from mod, would work fine, until switching language to another, lead to crash to desctop with:
Trying to call FMOD_RESULT __stdcall AudioClip::ScriptPCMReadCallback(struct FMOD_SOUND *,void *,unsigned int) on non-legacy AudioClip!
I couldn't reproduce it, even on Steam. What operating system are you using? Could you please upload the minimal example of a mod causing these issues?
No more info. Could be a Unity bug.