Placing an Express VI Causes Error -191231 "Unable to View Properties"

Updated Dec 22, 2023

Reported In


  • LabVIEW 2016 Full
  • LabVIEW 2016 Report Generation Toolkit


  • Report Generation Toolkit 16

Issue Details

When I try to place an Express VI on my block diagram, I receive Error -191231 Unable to View Properties. Why do I receive this error?


You may receive this error if you try to use LabVIEW immediately after installing one or more drivers without first rebooting your computer. This can happen if you download and install a specific driver from or if you run the installation from the NI Device Drivers CD that ships with LabVIEW. You will need to reboot your computer to complete the installation. After rebooting, you should no longer receive this error.

If this error happens with the DAQ Assistant Express VI make sure that your LabVIEW and DAQmx versions are compatible.

You may also see this error if you have modified a VI in the vi.lib folder of your LabVIEW installation. The configuration dialog box that is launched when you place an Express VI on the block diagram is stored in vi.lib. If you have changed or caused a broken run arrow in the configuration dialog for an Express VI or any subVI used by it, you will need to correct the errors before you can use the Express VI. If you are unable to locate or correct the problem, you will need to repair or reinstall your LabVIEW installation.

It is also possible to get this error if you have a VI loaded in memory that has exactly the same name as a VI in vi.lib that is used by the Express VI. If this is the case, you can close out of the relevant VIs or projects or restart LabVIEW. You may need to rename your conflicting VI if you need to use the Express VI in the same project or hierarchy.

This error can also occur if the license of your Report Generation Toolkit has expired. Even though you can still drop these Express VIs on the block diagram using Quick Drop, it can result in the above error.