When you create an executable or shared library from LV, it requires the LV runtime engine of that version. So, if you created the EXE or DLL in 5.0, you will need to install the 5.0 runtime engine to run it, or you can create a new EXE/DLL in 6.0. (The LV development system will know how to update the VIs from 5.0 to 6.0, but not the runtime engine.)