PRB: Loading COM DLL from ASP Stops IIS if FoxUser is Corrupted

• Microsoft Visual FoxPro for Windows, version 6.0

SYMPTOMS

Loading an ASP that calls a Visual FoxPro COM DLL stops the FTP Publishing Service and the World Wide Web Publishing Service (WWW) on the Windows NT Server that is running Internet Information Server (IIS).

CAUSE

This is known to happen if the FoxUser.dbf resource file that the Visual FoxPro runtime that the COM DLL is using is corrupted.

RESOLUTION

There are at least two resolutions to this:

• Delete the corrupted FoxUser file. The Visual FoxPro runtime will recreate one. Alternately, a valid FoxUser resource file can be provided.



• Add a Config.fpw file as an included file in the project when building the COM DLL. This Config.fpw file should contain the RESOURCE=OFF command. This will prevent the COM DLL from trying to use a resource file.


Please note that in Visual Studio 6.0 SP3 for Visual FoxPro, the FoxUser file is no longer created or loaded by the runtime when loading a COM DLL.

STATUS

This behavior is by design.

MORE INFORMATION

The resource file is a Visual FoxPro table that contains information on system and user-defined resources such as keyboard macros, preferences, system window locations and sizes, diary entries, and so on. By default, it is named FoxUser.dbf.

The SET RESOURCE TO <filename> command can be used within Visual FoxPro or a Visual FoxPro runtime to set the resource file to the desired file. The SYS(2005) function can be used to determine the name and location of the resource file. The SET("Resource") command can be used to determine if the resource file is being used. SYS(2005) will still report the name and location of the resource file even if it is not currently being used.

Trying to load a Visual FoxPro COM DLL that uses a runtime that tries to use a corrupted resource file will generate the following error messages in Visual FoxPro and Visual Basic or Visual Basic for Applications:

In a Visual FoxPro runtime exe (with RESOURCE=OFF in its Config.fpw):

OLE error code 0x80040154: Class not registered

Run-time Error '429'
ActiveX component can't create object.

Steps to Reproduce Behavior

1. Obtain the following Microsoft Knowledge Base article:




Q168053 HOWTO: Use VFP Automation Servers with Active Server Pages

2. Implement it on Internet Information Server(IIS) so that it functions properly.



3. Find the FoxUser.dbf file that the Visual FoxPro runtime is using. A good place to look is in the \Winnt\System32 directory on the Windows NT Server. To facilitate determining the FoxUser file being used by the runtime, the following code can be added to the Visual FoxPro code in the article after the other two procedures but before the ENDDEFINE:




	PROCEDURE getresource
		x=SYS(2005)
		IF !EMPTY(x)
			RETURN x+" and it is "+SET("Resource")
		ELSE
			RETURN "There is no resource file"
		ENDIF
	ENDPROC 

4. Rebuild the COM DLL and replace the ASPSrv.dll, ASPSrv.vbr, and ASPSrv.tlb on the NT Server. Then the following lines of code can be added to the Active Server Page, right above the </BODY> tag:




<P>
The Resource File info is: <%VFPSrv.GetResource()%>
<P> 

5. Load the ASP after these modifications and it will report the FoxUser file being used.



6. Corrupt the FoxUser that the Visual FoxPro runtime is using. An easy way to do this is to open FoxUser.dbf in Notepad and delete the first couple of lines in it. Note that the FTP Publishing and WWW Publishing services on the NT Server may need to be stopped to allow access to the FoxUser file. Be sure to restart them after corrupting the FoxUser file.



7. Open the Services control panel on the Windows NT Server. Locate the World Wide Web Publishing Service. Note that is should currently be Started.



8. Reload the ASP and then check the WWW Publishing Service in the Services control panel. It should now be Stopped. The Services control panel may need closed and reopened to refresh. Internet Explorer should also report the following:

   Internet Explorer cannot open the Internet site http://yourserver/VFPSrv.ASP.
   A connection with the server could not be established

REFERENCES

For additional information about use Visual FoxPro COM DLLs with Active Server Pages, please see the following article in the Microsoft Knowledge Base:

Q168053 HOWTO: Use VFP Automation Servers with Active Server Pages

Additional query words:

Keywords : kbAppSetup kbCOMt kbInternet kbOOP kbVFp600 kbGrpFox
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbprb