Ask about Debug Assert Failed
I develop my friend's program. He already build file .exe in both debug and release vesion. I edit his source code in debug vesion .I edit both header file (.h) and implement file (.cpp) and I try to build .exe file. I can build it.But when I run .exe file it can run but there is error message box happen.

In the header of Message Box has this message "Microsoft Visual C++ Debug Library"
And in the Box have this message

Debug Assertion Failed
File: afx.inl
Line: 122

For information on how your program can cause assertion failure, see the Visual C++ documentation on asserts.

(Please Retry to debug the application.)
There are Abort Retry Ignore Button in the message box I push Retry and Ignore then there are error message.
Extract has caused an error in MFC42D.DLL.
Extract will now close.

I want to know how to solve this problem and I have another question. I saw in my friend's header file
There are this text.

#if !defined(AFX_EXTRACT_H__B3A92CA1_CE5F_11D3_B2F3_C9 3CE10BBB05__INCLUDED_)
#define AFX_EXTRACT_H__B3A92CA1_CE5F_11D3_B2F3_C93CE10BBB0 5__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "cdib.h"

I want to know about text before #include "cdib.h"
When the computer build that text? Is it the cause of the assertion failure?
Thank you for your answer.