Embedding a C++ program in a game project

Unfortunatly I cannot do that the compiler says I need common.h as first include:

EXEC : error : All source files in module "unreal_dontmakelove" must include the same precompiled header first.  Currently "[...]\Source\unreal_dontmakelove\ChatScript-6.2.b\SRC\common.h" is included by most of the source files.  The following source files are not including "[...]\Source\unreal_dontmakelove\ChatScript-6.2.b\SRC\common.h" as their first include:
    1>
    1>  [...]\Source\unreal_dontmakelove\ChatbotEngineCore.cpp (including C:\Program Files (x86)\Epic Games\4.10\Engine\Source\Runtime\Core\Public\Windows\AllowWindowsPlatformTypes.h)
    1>  [...]\Source\unreal_dontmakelove\unreal_dontmakelove.cpp (including C:\Program Files (x86)\Epic Games\4.10\Engine\Source\Runtime\Core\Public\Windows\AllowWindowsPlatformTypes.h)

By the way windows.h is included inside common.h I tried nonetheless to include it again as second in the unreal files, but the compiler still gives the same errors.