Dear all, I think that the tool tracer has a problem with reading lines longer than 255 characters. The array "str" declared in "tracer.cpp" has only 255 places, but a line of output from verifyta can be longer. I suggest that, in order to solve the problem, you could simply change the 255 values to a much higher value, like 5000 (both in the declaration of the "str" array and in the calls to function read).