Problem with monkeyc -e.

When I run the command

"monkeyc -f monkey2.jungle -e -o deluxe.iq -y key"

to make a publishable executable, I get the error "ERROR: null".

A couple of months ago it still worked (I only made a minor change in the source code).

When I, on the contrary, make an executable for the simulator with

"monkeyc -f monkey2.jungle -o deluxe.prg -y key"

it still works (with the same source code), and I can run "deluxe.prg" without problems in the simulator.

Anyone has an idea what goes wrong?

(I'm on an iMac)