Copied Post-Process water effect errors


I have copied the Post-Process water effect and all the files it uses from the jme3 source code, because I mant to modify it to make it fully suit my needs. Unfortunately, I can’t get it to work, because a shader gives me this error:

I didn’t change anything yet, eccept for the paths.

When I use only the copied WaterFilter and ReflectionProcessor and let them use the files of the library, it doesn’t error, but when you are above water, the screen flashes with random greenish colours when above water (and the entire screen is that colour, you can’t see anything), and when you are below water, the scene is visible with the fog, but there are no caustics and you can’t see the bottom of the water plane.

Does anyone know how to fix this error?

Many thanks in advance for your help.