“Undefined Symbol” Error at FP_Open in LabWindows™/CVI™

Updated Apr 18, 2023

Reported In


  • LabWindows/CVI Base


  • NI FieldPoint

Issue Details

When I try to compile my FieldPoint LabWindows/CVI project, I get an "Undefined Symbol" error at FP_Open. It seems as though LabWindows/CVI can’t find the FieldPoint library. How can I troubleshoot this error? 


There are a few troubleshooting steps to go through: 
  1. Make sure that the Debug mode in LabWindows/CVI is set correctly. In Build»Configuration, verify that you are in Debug mode and not Debug64.
  2. Try manually adding the FieldPoint.fp file to the project. To do this, right-click Libraries»Add, then navigate to the FieldPoint.fp file. This can help if multiple versions of LabWindows/CVI were installed on the same PC at the time of the original FieldPoint installation, as the driver install only applies FieldPoint support to the most recent version of LabWindows/CVI on that machine.
  3. If this does not work, uninstall and reinstall the FieldPoint driver.
  4. If available, try upgrading to a newer version of LabWindows/CVI and linking the FieldPoint.fp library directly to shared/cvi/bin.
  5. Completely uninstall LabWindows/CVI and the FieldPoint driver, and then reinstall LabWindows/CVI, then the FieldPoint driver.
If you have gone through all of these steps and are still seeing the error, contact National Instruments for support.