Error -17701 When Running or Debugging TestStand Sequences

Updated Mar 15, 2023

Reported In


  • TestStand
  • LabWindows/CVI

Issue Details

  • I have a sequence that contains several LabWindows™/CVI™ steps. When I run my sequence or while single stepping during debugging, I receive error -17701:
Error calling sequence MainSequence. Error loading step 'your step' of sequence 'your sequence' in file 'your sequence file'. Unable to launch CVI. Error Code: -17701, Source: 'TSAPI'

Why is this happening, and how can I successfully run or debug my sequence?
  • I'm getting the following error:
Error code -17703 The CVI automation server is not registered on this machine.
How can I fix this?


There are several possible reasons for receiving this error, including: 
  • LabWindows/CVI is not installed on the machine and the LabWindows/CVI adapter is configured to execute steps in an external instance of LabWindows/CVI. When using this adapter configuration, you are required to have LabWindows/CVI installed. If you do not have it installed, you can change the adapter configuration to execute steps in-process. First open TestStand and navigate to Configure»Adapters.  In the window that appears, select the LabWindows/CVI adapter and click Configure. Then select Execute Steps In-Process (LabWindows/CVI is not Required for this Mode) and click OK.

  • The LabWindows/CVI Automation Server is not registered or not responding on this machine. In this case, make sure LabWindows/CVI and TestStand can successfully communicate through ActiveX. Verify this by running one of the TestStand shipping examples that use LabWindows/CVI. For example, run AccessingPropertiesAndVariables.seq located in the <TestStand>\Examples\AccessingPropertiesUsingAPI\UsingCVI directory. If the examples do not work, try repairing or reinstalling TestStand.
  • If this error only occurs during debugging, it is likely that you are trying to step into a LabWindows/CVI code module but do not have the development environment activated.  In this case, activate LabWindows/CVI or choose to Step Over the step instead of into it.  Stepping Over will not try to launch LabWindows/CVI.