Microsoft KB Archive/110873

PRB: DDE Warning Message: Invalid Value: -32767 PSS ID Number: Q110873 Article last modified on 05-10-1994

3.10

WINDOWS

= SYMPTOMS =

When executing a call to DdeClientTransaction from a Microsoft Foundation Class (MFC) Library application in the debug version of Windows 3.1, the following warning message is displayed in the debug monitor:

wn CLIENTAPP CallNextHookEx + 2C: Invalid value: -32767

= CAUSE =

This error message is caused by the _AfxMsgFilterHook hook procedure installed by the MFC. This hook procedure, found in line 408 of the APPCORE.CPP file of the MFC 1.0 source, incorrectly passes internal DDEML messages to the CallNextHookEx function. When the hook procedure receives a MSGF_DDEMGR message, it should instead return FALSE.

For additional information on processing DDEML messages from a WH_MSGFILTER hook procedure, please see the following article(s) in the Microsoft Knowledge Base:

ARTICLE-ID: Q89828 TITLE : INF: Do Not Forward DDEML Messages from a Hook Procedure

= RESOLUTION =

Although this warning message is generally harmless, one way to keep this message from coming up is to modify the _AfxMsgFilterHook function in the APPCORE.CPP file (found in directory for Microsoft Visual C++ version 1.0) to return FALSE if (code == MSGF_DDEMGR), as the Microsoft Knowledge Base article referenced above recommends, and then rebuild the library.

= STATUS =

Microsoft has confirmed this to be a problem in Microsoft Foundation Classes version 1.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional reference words: 3.10 KBCategory: Prg KBSubcategory: UsrDde

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Copyright Microsoft Corporation 1994.