PCGen 6.09.01 does not start in Linux

After extracting the 6.09.01 ZIP package from the website, entering the working directory of it, and running "./pcgen.sh", on both Arch Linux and Linux Mint, with various versions of OpenJDK/OpenJFX and Oracle Java, PCGen fails to start. Below are various samples of output with different configurations:

Arch Linux, Oracle Java 13:

OpenJDK 11 with OpenJFX 11 installed:

Arch Linux, OpenJDK 12 with OpenJFX 12 installed:

Arch Linux, Oracle Java 13 using "-Dprism.verbose=true -Djavafx.verbose=true":

I also tried it on the Linux Mint live CD, which has OpenJDK 11, and the output looked the same as the OpenJDK 11 output above.