I have three particle systems - everything works in Editor. Particles don't work in Build though - Windows x64. Have tried all quality modes in the res dialog, have tried explicitly playing each system and nothing. Tried setting sorting order from the default 0, to 1 and also nothing. Only "odd" thing I'm doing is using an Ortho camera and rendering to a render texture in front of the main camera. But no issue in Editor... any reason they wouldn't show in a Build?