Knowledge Base

PRB: Clireg32 Fails to Register the Type Library of DCOM Server

Article ID: 185193

Article Last Modified on 11/18/2003

APPLIES TO

Microsoft Visual Basic 5.0 Learning Edition
Microsoft Visual Basic 5.0 Professional Edition
Microsoft Visual Basic 5.0 Enterprise Edition

This article was previously published under Q185193

SYMPTOMS

When using Clireg32.exe to register the type library (.tlb file) of a DCOM server, the type library entries are not entered in the registry. This problem also occurs during the Internet download of usercontrols that reference DCOM servers. When this problem occurs, you will receive one of the following error messages while trying to run the DCOM client application:

The instruction at '0x00000000' referenced memory at '0x00000000'. The
memory could not be 'read'

-or-

An application error has occurred and an application error log is being
generated. '<Client.exe>' Exception: access violation (0xc0000005),
address: 0x00000000

CAUSE

The Clireg32.exe utility fails to register the type library when the DCOM option is selected.

RESOLUTION

To resolve this issue, modify the DCOM Server .vbr file, and then use CliReg32.Exe to reregister the DCOM Server, first as a remote automation component, then as a DCOM component, as detailed below.

Step-By-Step Procedure

Open the DCOM Server .vbr file in Notepad or any text editor.
Both the ProxyStubClsid and ProxyStubClsid32 keys for the DCOM Server ClassId must modified. (In the sample below, the underscore character (_) is used as a line-continuation character; the line does not appear in this way in your .vbr file.)

Change the following

HKEY_CLASSES_ROOT\INTERFACE\{<Server ClsId>} _
\ProxyStubClsid\{00020420-0000-0000-c000-00000000046}

to the following:

HKEY_CLASSES_ROOT\INTERFACE\{<Server ClsId>} _
\ProxyStubClsid\{00020424-0000-0000-c000-00000000046}

Make the same change for ProxyStubClsid32.
On the Windows Start menu, click Run, and type the following command:

CLIREG32 DCOMSERVER.VBR -T DCOMSERVER.TLB -S SERVERMACHINENAME

NOTE: In the above command, "DCOMSERVER" is the name of your DCOM server, and "SERVERMACHINENAME" is the name of the server where the DCOM component will reside. Choose Remote Automation from Remote Transport options.
Now, run the command again:

CLIREG32 DCOMSERVER.VBR -T DCOMSERVER.TLB -S SERVERMACHINENAME

This time, choose Distributed COM from Remote Transport options.

MORE INFORMATION

Steps to Reproduce Behavior

NOTE: This article assumes that you are familiar with creating and deploying DCOM client and server applications.

Create the DCOM Server

Create a new ActiveX EXE project in Visual Basic 5; Class1 is created by default.
Rename Class1 to "CDCOMServer".
On the Project menu, click Project Properties, and rename the project to DCOMServer.
Click the Component tab, and then click Remote Server Files.

Add the following code to the CDCOMServer class module:

    Private mName As String

    Public Property Let sName(str As String)
        mName = str
    End Property

    Public Property Get sName() As String
        sName = mName
    End Property

    Private Sub Class_Initialize()
        mName = "DCOM Server"
    End Sub

Create the ActiveX EXE.

Create the Client

Create a new ActiveX Control project in Visual Basic 5.0; UserControl1 is created by default.
Rename UserControl1 to "CtlDownload" (without the quotation marks).
Add a TextBox, a CommandButton, and a Label to the control.
On the Project menu, click References, and then click DCOMServer.

Place the following code in the user control's code pane:

    Private Sub Command1_Click()
        Dim svr As New DCOMServer.CDCOMServer
        svr.sName = Text1.Text
        Label1.Caption = svr.sName
    End Sub

[Optional] For testing, create a Standard EXE project to test the ActiveX control. Whenever you enter something in the TextBox and click Command1, the same text should be displayed on the Label.
Create the CtlDownload OCX.

Create Installation Programs for the Client and the Server

Use the Application Setup Wizard to create a setup program for DCOMServer project.
Create an Internet Component Download Setup for the client (CtlDownload). Be sure to add the DCOMServer.vbr file.

NOTE: To have a successful download, please refer to the following Microsoft Knowledge Base article:

168429 PRB: Component Download Fails for DCOM Projects

Install the Server and Test the Client

Install the DCOMServer on a Windows 2000 (Professional or Server) or Windows NT 4.0 (workstation or server) with Service Pack 3 installed.
From a client computer, open the CtlDownLoad.htm file in the control's setup folder.
Click the CommandButton on the control to reproduce one of the above-mentioned errors.

REFERENCES

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:

161837 HOWTO: Create a DCOM Client/Server Application

168429 PRB: Component Download Fails for DCOM Projects

266717 HOWTO: Create a DCOM Client/Server Application by Using VB

267836 HOWTO: Create a DCOM Client/Server with Events by Using Visual Basic

268550 HOWTO: Use Dcomcnfg for a Visual Basic DCOM Client/Server Application

269330 HOWTO: Troubleshoot DCOM for Visual Basic Client/Server Applications

Additional query words: DCOM Internet Download CliReg32.exe

Keywords: kbdcom kbprb kbctrl kbpending kbcontrol KB185193

Microsoft KB Archive/185193

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