Today I must have messed up things, as I cannot print my books anymore. I normally print to JPEGs and use these later on, but when pressing the Print … button nothing happens (likewise for command-p, etc).

My images are referenced, and I am using Aperture 3.4.5 on OS X 10.7.5, on an iMac 4.5 years old (4Gb).

Anyone any clues or hints?

Jeroen