The program does not work correctly, how to fix it?

Question

Java

Hello everyone guys.
I have a program which is written in Java.
It starts and everything is fine, but if you perform some functions in it, the program gives an error.
For example:
I go into the program, there is a "Menu" section, I press it and it gives an error

The folder with the program already has jre1.8 and pgsql as well as Readme and here is its brief description:

I don’t understand how to do all this at all. Is there anyone here who can help me? I will be very grateful! Thank you!