Hi all, I am newbie and I am developing in C++ using VC9, Boost 1.37, CPLEX 11.1. I use date_time and program_options boost libraries and my program compiles fine. Date_time works perfectly while program_options gives me a runtime error saying "Debug assertion failed .... string iterator not dereferencable" every time I pass any argument in the command line. The assertion fails at line 112 of "C:\program files\microsoft visual studio 9.0\vc\include\xstring" So I try to figure out what was going on in the following way: - I tried "first.cpp" in program option example directory on a new project: it works with no problem. -Then I tried to replace the main function of my project with the exact code of "first.ccp" and I got "string iterator not dereferencable" again. Can anyone help me ? Many thanks in advance Alessandro