Web Publishing Tool: Cannot Preview a Web Page

Updated May 10, 2019

Reported In


  • LabVIEW

Operating System

  • Windows


  • LabVIEW Web Server
  • LabVIEW Remote Panel Server
  • Optional: cRIO or other real-time embedded target

Issue Details

I cannot preview a web page when using the Web Publishing Tool in LabVIEW. I launch Web Publishing Tool and the wizard launches. I click Start Web Server and it appears grayed out and pressed. However, when I click Preview in Browser, I get a prompt saying that the web server has not been started.

You must start the LabVIEW web server before previewing your web page. Would you like to start the web server now?


  1. Check what LabVIEW is using for Remote Panel Server port. The default is 8000. You can check from Tools >> Options >> Web Server. Ensure that the Remote Panel Server is enabled and note the port number.
  2. Use netstat command to check what application is running on this port. Open the Command Prompt and run the following command:  netstat -o -n -a | findstr 0.0:8000 where 8000 is the port being used by Remote Panel Server.
  3. This will return information with the format TCP LISTENING <XXXX> where XXXX is the process identifier (PID).  No Internet Access When LabVIEW Is Installed describes how to find process from PID in Windows, see the Additional Information section. The Remote Panel Server will appear as LabVIEW.exe if running properly.
  4. End the application that is blocking the Remote Panel Server port. If this application cannot be ended, configure Remote Panel Server to use a different port.

Additional Information

This behavior occurs when another application is blocking the LabVIEW Remote Panel Server port. If you are still having issues accessing your webpage, see Error 404 Page Cannot Be Found When Using Remote Front Panels and Web Services.


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