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

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 5.0

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, the DCOM Server .vbr file must first be modified. 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

1. Open the DCOM Server .vbr file in Notepad or any text editor.



2. 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_CLASES_ROOT\INTERFACE\{<Server ClsId>} _
   \ProxyStubClsid\{00020420-0000-0000-c000-00000000046}
   
   to the following:
   
   HKEY_CLASES_ROOT\INTERFACE\{<Server ClsId>} _
   \ProxyStubClsid\{00020424-0000-0000-c000-00000000046}
   
   Make the same change for ProxyStubClsid32.



3. On the Windows Start menu, click Run, and enter 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.



4. Now, run the command again:
   
   CLIREG32 DCOMSERVER.VBR -T DCOMSERVER.TLB -S SERVERMACHINENAME
   
   This time, choose Distributed COM from Remote Transport options.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce

Create the DCOM Server

1. Create a new ActiveX EXE project in Visual Basic 5, Class1 is created by default.



2. Rename Class1 to "CDCOMServer"



3. On the Project menu, click Project Properties, and rename the project to DCOMServer.



4. Click the Component tab, and select Remote Server Files.



5. 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
    




6. Create the ActiveX EXE.

Create the Client

1. Create a new ActiveX Control project in Visual Basic 5.0; UserControl1 is created by default.



2. Rename UserControl1 to "CtlDownload" (without the quotation marks).



3. Add a TextBox, a CommandButton, and a Label to the control.



4. On the Project menu, click References, and click DCOMServer.



5. 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 




6. [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.



7. Create the CtlDownload OCX.

Create Installation Programs for the Client and the Server

1. Use the Application Setup Wizard to create a setup program for DCOMServer project.



2. 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:
   

   Q168429 : PRB: Component Download Fails for DCOM Projects

Install the Server and Test the Client

1. Install the DCOMServer on a Windows NT 4.0 (workstation or server) with Service Pack 3 installed.



2. From a client machine, open the CtlDownLoad.HTM file in the control's setup folder.



3. Click the CommandButton on the control to reproduce one of the errors described above.

REFERENCES

For additional information, please see the following articles in the Microsoft Knowledge Base:

Q161837 : HOWTO: Create a DCOM Client/Server Application

Q168429 : PRB: Component Download Fails for DCOM Projects

Additional query words: DCOM Internet Download CliReg32.exe kbDCOM kbActiveX kbCtrl

Keywords : kbCtrl kbGrpVB
Version : WINDOWS:5.0
Platform : WINDOWS
Issue type : kbprb