If you use Ubuntu (and this probably happens in other Linux ditros as well) and soapUI spits out a Exception in thread "XpcMessageLoop" java.lang.NullPointerException, here's a simple "fix" for it: edit bin/soapui.sh and uncomment the line

#   JAVA_OPTS="$JAVA_OPTS -Dsoapui.jxbrowser.disable=true"

so that it becomes

    JAVA_OPTS="$JAVA_OPTS -Dsoapui.jxbrowser.disable=true"

This is something I've ran into a few times in the past and I'm not sure why it hasn't been fixed yet but I decided to document it here anyway, at least for my own future reference, since apparently I'll have to do it every time I download a new version of soapUI.