Screen does not open, when I use FFT()

Hi, I used the sample, which comes on the processing homepage together with the description of FFT. You find it here:

https://processing.org/reference/libraries/sound/FFT.html

After changing my code for about 3-4 times the screen does not open up anymore and I get the message:

JAVA(TM) Platform SE binary does not work anymore, (no further explanations).

I have to restart my computer to continue writing on my file.

Do you have an idea, what I can change to avoid this error?

Thanks a lot in advance, Detlev