Sounds like all of the PC-side software works except for navX-UI. The navX-UI has problems on some systems when it is running 32-bit Java. The first thing I’d recommend checking is what version of java you have installed on your system.
Java 7 (version 1.7) or Java 8 (version 1.8) are required, the 64-bit version of Java is recommended and in some cases we find it is required. To tell which version of java is currently “Active”, open up a command window, and type this command:
java -version
So please run that check and if you find the version of java is not 7 or 8 and is not 64-bit, please update your system.
If you have a 32-bit operating system, check that you have 32-bit java installed.