SoapUI Pro 5.1.2 hangs on Mac OS X 10.8.5

The steps on http://www.bencode.net/blog/2015/01/25/soapui-freezing-osx/ worked for me (on OS X 10.10.3):

1. Start ‘Activity Monitor’ and Force Kill your dead soapUI process. [Or use Command-Option-Escape to force quit it.]
2. In Finder, /Applications/SmartBear/soapUI-5.0.0.app > Show Package Contents.
3. Edit /Applications/SmartBear/soapUI-5.0.0.app/Contents/java/app/bin/soapui.sh.
4. Uncomment this line# JAVA_OPTS="$JAVA_OPTS -Dsoapui.browser.disabled=true". [In other words, remove the "#" to stop it being a comment.]
5. Edit /Applications/SmartBear/soapUI-5.0.0.app/Contents/vmoptions.txt.
6. Add -Dsoapui.browser.disabled=true.
7. Start soapUI.

[In those paths, change soapUI-5.0.0 to match your version. For me it is soapUI-5.1.3.]

Hope this helps.