Applies To:
  • CitectSCADA 6.00
  • CitectHMI 6.00

I am setting up the CitectSCADA WebServer on a computer running WinXP Pro and IIS 5.1. When I log into the web client configuration user interface with web client administrator privileges the “Error in server Error” system message is displayed. Only the "Run Manager Client" button is shown and no other deployment control button is available. The following screenshot demonstrates this:

This also occurs when logging in with local Administrator privileges, removing any chance that it could be a file permissions security issue. I have re-installed IIS and CitectSCADA WebServer many times without success.

I have matched up the following System Event (Administrative Tools >> Event Viewer >> System Events) to this problem:

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 36
Date: <date>
Time: <time>
User: N/A
Computer: <Computer name>
The server failed to load application '/LM/W3SVC/1/ROOT/CitectSCADA'. The error was 'Class not registered'.

For additional information specific to this message please visit the Microsoft Online Support site located at:
For more information, see Help and Support Center at

The following is a screenshot of this:


The source of the problem is unknown but there are three things you could try to resolve the issue:

a) If you are running Windows 2000, go to IIS, Default Web Site, right-click CitectSCADA and choose Properties. Select tab "Virtual Directory" and set "Application Protection" to "Low (IIS Process)".

b) Install your local IIS instance with the local “Administrator” account and not with a domain administrator account.

c) Open the Component Services Microsoft Management Console (MMC) and click to expand the Component Services and Computers nodes. If you receive the following error message – “Catalog error - An error occurred while processing the last operation: 80040154, Class not registered” you will need to follow the steps in to resolve this.

d) Try (b) and if you still receive the 'Class not registered' error message, then you need to recreate the IIS packages in COM+:

    1) Delete IIS related package in Component Services MMC
        • IIS In-Process Applications 
        • IIS Out-of-Process Pooled Applications 
        • IIS Utilities

    2) Open command prompt, navigate to %windir%\system32\inetsrv folder, and enter (case sensitive)
        c:\winnt\system32\inetsrv\>rundll32 wamreg.dll, CreateIISPackage
        c:\winnt\system32\inetsrv\>regsvr32 asptxn.dll

    3) Enter IISRESET at command prompt to restart IIS services, then re-open Component Services MMC to verify the IIS packages are recreated.


error in server error, web client, error, class not registered