I see, if you already have [CGMZ] Core, then you need to update it if you are getting that error. The parseSoundEffectJSON function comes from my core as multiple plugins of mine have sound effect parameters and I got tired of re-writing the same code over and over again to parse it out into a usable object for the actual code, so I put it in the core. The current version is 1.14.1 but that function was added in 1.12.0 of my core. If you delete the sound effect setup then no sound effect will be able to play.
The splash animation works via spritesheet animation. What does your Splash Animation, animation frame width/height/speed/time parameters look like?
For swimming animation, you will need to create a swim sprite sheet for each actor, and then if that actor is the lead party member it will change their character walking sprite sheet to the swimming sprite sheet while they are swimming and change it back when they stop swimming.
