TestStand Error -17801: Unknown Interface ID

Updated Jul 31, 2023

Reported In


  • TestStand
  • LabVIEW

Issue Details

I am using TestStand to call a LabVIEW VI that has a Waveform Parameter. When I try to call the VI, I get Error Code: -17801; Unknown Interface ID. How do I fix this error?


This error usually occurs if you uninstall LabVIEW but leave a different version installed. It also can occur after a windows update.
To fix the problem, you will need to repair your LabVIEW installation.