This was an issue on earlier Mangos, but the new 3.6 upgrade overwrites the jssc-2.8.0.jar with the version that doesn't work on ARM. I'm using ARM for my data aquisition devices, and if you do the 3.6 upgrade it will re-install the nonworking jssc-2.8.0.jar file. So, you'll need to do what was suggested in Topic 4106 again:
apt-get install libjssc-java
cp /usr/share/java/jssc-2.8.0.jar /opt/mango/lib
Otherwise, you get error 500's when trying to edit a data source, and your serial comms won't work on the ARM platform.