Error Message
'filename' : alignment changed after including header, may be due to missing #pragma pack(pop)
Packing affects the layout of classes, and commonly, if packing changes across header files, there can be problems.
Use #pragma pack(pop) before exiting the header file to resolve this warning.
The following sample generates C4103:
// C4103.h
#pragma pack(push, 4)
// defintions and declarations
// uncomment the following line to resolve
// #pragma pack(pop)
And then,
// C4103.cpp
// compile with: /LD /W1
#include "c4103.h" // C4103