Sadly I really cannot help MacOSX anymore ☹ (with all the side-meanings this sentence can have - I switched to GNU Linux 10 years ago, because Apple does not adhere to user-rights while it controls both hardware and software, and they have been breaking advanced usage of their OS more and more since then)
The exception says that it’s a null-pointer in the Apple-specific part of the program. Likely Apple changed some API which wrecked the Apple-part of the program.
You could try to run the jar-file directly instead of using the phex.app:
- download
http://phex.sourceforge.net/snapshot..._3.4.2.163.zip
- unpack it
- go to <unpacked folder>/lib
- java -jar phex.jar
Does that work?