There has been a change in Grails 2.4 with the removal of the 'upgrade' command but with the IDEA that I am using 13.1 build 760 it is still present as part of the 'upgrade SDK' option but when running within Grails 2.4 it does fail
see http://grails.org/doc/2.4.x/guide/upgradingFrom23.html
I appreciate that this may be a little messy to deal with but I was surprised that it seems to fail completely silently - without showing the Grails console at all - when I ran it from the context menu - right click on open project name -> Grails -> Change SDK version. In fact this action results in the project no longer being a Grails project at all !
I did see the error when I gave up and ran the create project from existing sources, this time the console is visible with the very obvious error.
IDEA 13.1 build 760
graham