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in my application need some scanner support ,I thought it is a good idea to get into TWAIN and try it out.after that I had an exit error that is driving me nuts as an Debug Assertion Failed....
in cmdtarg.cpp line 40 CCmdTarget::~CCmdTarget because m_dwRef is greater than 1 (in this case it is 2)


What I have tried:

CCmdTarget::~CCmdTarget()
{
	if (m_xDispatch.m_vtbl != 0)
		((COleDispatchImpl*)&m_xDispatch)->Disconnect();
	ASSERT(m_dwRef <= 1);
	m_pModuleState = NULL;
}



//Error message

'ScannerApp.exe' (Win32): Unloaded 'C:\Windows\twain_32.dll'
Debug Assertion Failed!

Program: C:\Windows\SYSTEM32\mfc140d.dll
File: d:\a01\_work\11\s\src\vctools\VC7Libs\Ship\ATLMFC\Src\MFC\cmdtarg.cpp
Line: 40
Posted
Updated 9-Dec-22 8:58am

I don't have an answer for you because there isn't enough code posted to have one. I recommend that you check out some sample code to see if you are overlooking anything or just doing something incorrectly. Here are a few samples I found, two of which are here :
A C++ Wrapper for TWAIN[^]
A Copy Utility using TWAIN[^]
TWAIN sample Data Source and Application[^]
Hopefully one of them can help you.
 
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Take a look at m_dwRef assert in ~CCmdTarget[^]

It seems an object is not being released somewhere in your code, for whatever reason.
because m_dwRef is greater than 1 - Google Search[^]
 
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Assertion on

ASSERT(m_dwRef <= 1);


Means just one thing: You forgot to call Release() prior object was destroyed
 
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There is a hint that different versions of MFC combined in one project may have led to a similar problem.
m_dwRef assert in ~CCmdTarget[^]
 
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