Does vrc have a limit on how many sub emitters you can have on a particle system? I've got a cannon that has an explosion on impact, a set of rings that come out from the start, and a bunch of trailing particles that follow the shell all on sub emitters but only two of them work each upload. It seems to be random which ones but really I don't know.
The inspector menu for the particles went dark grey for some reason if that means anything too.