CKFile in VT21: 0xC8, 200, count50; in VT25: 0xE0, 224, count 56
lost 24 byte, 6 fields or 2 lists

m_FileName
in VT21 +34, 136
in VT25 +31, 124

m_MappedFile
in VT21 +37, 148
in VT25 +34, 136

m_Context
in VT21 +35, 140
in VT25 +32, 128

VxMemoryMappedFile and CKFileInfo seems no change
CKFileObject still no change
CKFilePluginDependencies still no change

CKStateChunk is 0x28u black box
CKBufferParser also is 0x10u black box

struct CKGUID {
DWORD d1,d2;
};

struct XBaseString {
	// the string 
	char*	m_Buffer;
	// the length of the string
	WORD	m_Length;
	// the allocated size
	WORD	m_Allocated;
};

struct XArray {
	// elements start {secret}
	DWORD*			m_Begin;
	// elements end {secret}
	DWORD*			m_End;
	// reserved end {secret}
	DWORD*			m_AllocatedEnd;
}
struct XClassArray {
	DWORD*			m_Begin;
	DWORD*			m_End;
	DWORD*			m_AllocatedEnd;
}
struct XSArray {
	DWORD*			m_Begin;
	DWORD*			m_End;
};
struct XBitArray {
    DWORD m_Data_Flags;
    DWORD m_Size;
};

struct CKFileInfo 
{
	DWORD				ProductVersion;		// Virtools Version (Dev/Creation). (CK_VIRTOOLS_VERSION)
	DWORD				ProductBuild;		// Virtools Build Number.
	DWORD				FileWriteMode;		// Options used to save this file. (CK_FILE_WRITEMODE)
	DWORD				FileVersion;		// Version of file format when file was saved.
	DWORD				CKVersion;			// Version of CK when file was saved.
	DWORD				FileSize;			// Size of file in bytes.
	DWORD				ObjectCount;		// Number of objects stored in the file. 	
	DWORD				ManagerCount;		// Number of managers which saved data in the file.
	DWORD				MaxIDSaved;			// Maximum Object identifier saved
	DWORD				Crc;				// Crc of data
	DWORD				Hdr1PackSize;		// Reserved
	DWORD				Hdr1UnPackSize;		// Reserved
	DWORD				DataPackSize;		// Reserved
	DWORD				DataUnPackSize;		// Reserved
};

struct CKFileObject {
	CK_ID			Object;			// ID of the object being load/saved (as it will be/was saved in the file)
	CK_ID			CreatedObject;	// ID of the object being created
	CK_CLASSID		ObjectCid;		// Class Identifier of the object
	CKObject*		ObjPtr;			// A pointer to the object itself (as CreatedObject when loading)
	CKSTRING		Name;			// Name of the Object
	CKStateChunk*	Data;			// A CKStateChunk that contains object information
	int				PostPackSize;	// When compressed chunk by chunk : size of Data after compression
	int				PrePackSize;	// When compressed chunk by chunk : size of Data before compression
	CK_FO_OPTIONS	Options;		// When loading an object it may be renamed , use to replace another object 	
	int				FileIndex;		// Position of the object data inside uncompressed file buffer
	CKDWORD			SaveFlags;		// Flags used when this object was saved.	
};

struct CKFilePluginDependencies{
	int				m_PluginCategory;
	XArray/*<CKGUID>*/  m_Guids;
	XBitArray		ValidGuids;
};

struct VxMemoryMappedFile {
    void*      m_hFile;
    void*      m_hFileMapping; // Handle of memory mapped file
    void*       m_pMemoryMappedFileBase;
    DWORD       m_cbFile;
    DWORD m_errCode;  
};

struct CKBufferParser {
    char* m_ReaderBegin;
    DWORD m_ReaderPos;
    CKBOOL m_NeedManualFree;
    DWORD m_ReaderSize;
};

struct CKFile {
// 0
	int							m_SaveIDMax;			// Maximum CK_ID found when saving or loading objects  {secret}
	XArray/*<CKFileObject>*/		m_FileObjects;			// List of objects being saved / loaded   {secret}
	XArray/*<CKFileManagerData>*/	m_ManagersData;			// Manager Data loaded  {secret}
	XClassArray/*<CKFilePluginDependencies>*/ m_PluginsDep;	// Plugins dependencies for this file  {secret}
	XClassArray/*<XIntArray>*/		m_IndexByClassId;		// List of index in the m_FileObjects table sorted by ClassID  {secret}
	XClassArray/*<XString>*/		m_IncludedFiles;		// List of files that should be inserted in the CMO file.  {secret}
// 16
    CKFileInfo					m_FileInfo;				// Headers summary  {secret}
// 16 + 14 = 30
    // guess
    DWORD unknow_fields;
	XBitArray					m_AlreadySavedMask;			// BitArray of IDs already saved  {secret}
// 30 + 3 = 33
	CKDWORD						m_Flags;				// Flags used to save file {secret}
	CKSTRING					m_FileName;				// Current file name  {secret}
	CKContext*					m_Context;				// CKContext on which file is loaded/Saved  {secret}
	CKBufferParser*				m_Parser;
	VxMemoryMappedFile*			m_MappedFile;
// 33 + 5 = 38
    // guess
    float   m_Chrono[5];
// 38 + 5 = 43
    //[guess]
	CKBOOL					m_SceneSaved;
	CKBOOL				m_ReadFileDataDone;
// 43 + 2 = 45
	XBitArray					m_AlreadyReferencedMask;	// BitArray of IDs already referenced  {secret}
	XObjectPointerArray			m_ReferencedObjects;
// 45 + 2 + 3 = 50
};
    
	VxTimeProfiler				m_Chrono;
    
	XFileObjectsTable			m_ObjectsHashTable;
//#ifdef USECHUNKTABLE
	XClassArray/*<CKFileChunk>*/	m_FileChunks;			// Instead of allocating chunk per chunk a whole memory buffer is allocated to store all chunks and their readers
	CKFileChunk*				m_ObjectChunks;
	CKFileChunk*				m_ManagersChunks;
	VxMemoryPool				m_ChunkBuffers;			// Store all decompressed file buffer in memory so that all chunks directly points to it...
														// can only work for recent files ( > 2.0)
	BYTE*						m_CurrentChunkBufferPtr;
//#endif					

	CKBOOL						m_ReadFileDataDone;
	CKBOOL						m_SceneSaved;
//-----------
	XIntArray					m_DuplicateNameFounds;	// A List of file object index for which a existing object with the same name has been
														// found, this list is build if the load option contains CK_LOAD_AUTOMATICMODE or CK_LOAD_DODIALOG

//----- 	
	XBitArray					m_AlreadySavedMask;			// BitArray of IDs already saved  {secret}
	XBitArray					m_AlreadyReferencedMask;	// BitArray of IDs already referenced  {secret}
	XObjectPointerArray			m_ReferencedObjects;
};