I'm trying to work out the map making tutorial here: http://www.qgistutorials.com/en/docs/making_a_map.html
When I try to export an image or pdf or even print the map I built in the composer, I receive no response, no dialog, nothing.
I tried QGIS 2.8 and 2.10. My computer is a Mac mini with OSX Yosemite and 4GB RAM. I couldn't find any log files to debug or anything.