I use the Uppaal 4.1.3 snapshot with stopwatches, and when I want to generate the compiled version of the timed automata to analyse the traces, with the environment variable UPPAAL_COMPILE_ONLY, Uppaal throw an "EXCEPTION: Cannot build expression". I guess it's because the part of Uppaal dedicated to the printing of the compiled model is not adapted to the new stopwatch feature, the problem is not present if I don't use any stopwatch. Simon