PRB: ActiveX Control Does Not Display Correctly on Web Page

• Microsoft ActiveX SDK, version 1.0
• Microsoft Internet Explorer (Programming), versions 3.0, 3.01, 3.02, 4.0

SYMPTOMS

In some cases an ActiveX control embedded on a Web page shows up in Internet Explorer as a white box with a red x in it. In other cases, the control does not display at all.

CAUSE

This problem can be caused by any one of the following:

• Missing dependent DLLs used by the ActiveX control
• Missing .lpk file when using a licensed ActiveX control
• ActiveX control contains other licensed controls requiring run-time license
• Missing CODEBASE attribute in the ActiveX control's <OBJECT> tag

RESOLUTION

Missing Dependent DLLs Used by the ActiveX Control

For a C++ control written in MFC, be sure to package the correct version of the MFC DLLs with the control, specifying them in the .inf file.

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

   ARTICLE-ID: Q167158
   TITLE     : How to Package MFC Controls For Use Over the Internet

   :
   :

   [Add.Code]
   SIMPLE.OCX=SIMPLE.OCX
   ASYCFILT.DLL=ASYCFILT.DLL
   MSVBVM50.DLL=MSVBVM50.DLL

   :

   [ASYCFILT.DLL]
   hook=AsycFilt.cab_Installer
   FileVersion=2,20,4056,1
    [AsycFilt.cab_Installer]
   file-win32-x86=http://activex.microsoft.com/controls/vb5/AsycFilt.cab
   InfFile=AsycFilt.inf
    [MSVBVM50.DLL]
   hook=MSVBVM50.cab_Installer
   FileVersion=5,0,37,24
    [MSVBVM50.cab_Installer]
   file-win32-x86=http://activex.microsoft.com/controls/vb5/MSVBVM50.cab
   InfFile=MSVBVM50.inf

The easiest way to work around this problem is to run the Registry Editor, Regedit.exe, and search on the dependent DLLs name to find out the expected location of the missing dependent DLL. If the file no longer exists in that directory, manually copy the DLL into that location. Restart Internet Explorer and navigate to the page containing the ActiveX control and see if it displays correctly.

WARNING: Using Registry Editor incorrectly can cause serious, system- wide problems that may require you to reinstall Windows to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Missing .lpk File when Using a Licensed ActiveX Control

A common symptom of this problem is that the ActiveX control displays correctly in the development machine, but not on others.

To use licensed controls in an HTML page on a non-licensed computer, you must generate a license package file (.lpk) and insert an <OBJECT> tag for the License Manager object before the actual <OBJECT> tag for the ActiveX controls.

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

   ARTICLE-ID: Q159923
   TITLE     : HOWTO: Using Licensed ActiveX Controls in Internet Explorer

ActiveX Control Contains Other Licensed Controls Requiring Run-Time License

An example of this is an ActiveX control that contains the Visual Basic 4.0 version of the Mscomm32.ocx, which is a licensed control. The ActiveX control displays correctly on any machine that that Visual Basic or Visual C++ installed because VB and VC++ provide run-time licenses for these controls automatically when installed.

To work around this problem, find a non-licensed version of the same control, or another third-party control with the same functionality. In the case of the licensed Mscomm32.ocx, the version of Mscomm32.ocx that was distributed with Visual Basic 5.0 is not licensed and can be used. This control may be downloaded directly from http://activex.microsoft.com/controls/vb5/mscomm32.cab.

Missing CODEBASE Attribute in the ActiveX Control's <OBJECT> Tag

 A machine that does not have the ActiveX control already installed will

Always specify a CODEBASE attribute in the control's <OBJECT> tag, pointing to the correct download location for the control.

For example, when inserting an HTML Layout Control in your HTML page, be sure to set the Codebase attribute on the Object tag for the HTML Layout Control as follows:

   <OBJECT CLASSID="CLSID:812AE312-8B8E-11CF-93C8-00AA00C08FDF"
      ID="Layout1_alx" STYLE="LEFT:0;TOP:0"
      CODEBASE="http://activex.microsoft.com/controls/
                MSpert10.cab#Version=1,0,5,1">
      <PARAM NAME="ALXPATH" REF VALUE="Layout1.alx">
   </OBJECT>

REFERENCES

For additional information, please see the following article(s) in

   the Microsoft Knowledge Base:

   ARTICLE-ID: Q167597
   TITLE     : FILE: Specifying FileVersion and #Version for Component
               Download

   ARTICLE-ID: Q165075
   TITLE     : HOWTO: Downloading Dependent DLLs in IE with .inf File