This article was previously published under Q295330
This article has been archived. It is offered "as is" and will no longer be updated.
You may encounter an access violation if you unload a form that contains the WinInet ActiveX control when that form is hosted in a Visual Basic Component Object Model (COM) dynamic link library (DLL) rather than in the main project.
Under certain conditions, destruction of the loaded WinInet control in a COM DLL may partially fail. The control creates a hidden window that is used for message handling. Although the control is successfully unloaded under all conditions, the hidden window may survive the destruction of the control. Because the window's callback function is destroyed when the control is unloaded, messages that are sent to the hidden window result in an access violation.
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.
Note You must have a Visual Studio license agreement to obtain this hotfix.
To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:
Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name Platform ------------------------------------------------------------- 6.00.8877 Msinet.ocx
Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article. This bug was corrected in Visual Studio Service Pack 6.
Microsoft Visual Basic 6.0 Enterprise Edition, Microsoft Visual Basic 6.0 Enterprise Edition Service Pack 3, Microsoft Visual Basic 6.0 Enterprise Edition Service Pack 4, Microsoft Visual Basic 6.0 Enterprise Edition Service Pack 5, Microsoft Windows Internet Services (WinInet)