Hello there, I've just started using Boost.Python, and find it absolutely invaluable. For the moment, my main task is embedding the python interpreter within an application of mine, and I have successfully built a small application that can load a module, execute a Python function and then collect the result. The next logical step was to extend the Python script somewhat into objects. I wrote some extra code in the script which I checked with the command line interpreter and verified to work. Before changing the C++ code to actually /use/ these new objects, I decided to just see what would happen if I kept exactly the same C++ code but with the new Python script (which still contains the function used for the last example). It ran fine - producing the correct output - but then exited abruptly with the following message: "Fatal Python error: PyThreadState_Get: no current thread". The changes to the original script file were the addition of two new classes - OptionsGUI and Button - and, oddly, commenting out Button makes the program work again (I say oddly because it's simply a class with a constructor, nothing more). Evidently I'm using the library incorrectly, and have searched through the documentation for things I might have done wrong but alas, I do find it rather daunting. I also noticed that my code is quite different from examples - is this a correct way to be doing things? And yes, at present, I'm not doing any exception or error handling - I'm a little unclear on it but I'm sure I will be able to do it given time :) For those wishing to look at the source, I have put the two files - EmbeddedPythonFunc.cpp and script2.py - in my webspace to prevent everyone having to download them as attachments. They are available at the following addresses: http://kutsurogu.pwp.blueyonder.co.uk/EmbeddedPythonFunc.cpp http://kutsurogu.pwp.blueyonder.co.uk/script2.py (incidentally, I didn't include stdafx.h because it simply includes iostream, tchar.h and boost/python.hpp). I hope I have sent my help request to the right place! Apologies if I have not. Thank you in advance, Ed Fear