Error 1761 When Calling Python Function From LabVIEW

Updated Mar 9, 2026

Reported In

Software

  • LabVIEW

Issue Details

When calling a Python function from LabVIEW using Python Node in the shipping example PythonNode_AddTwoDoubles.vi, the execution fails with Error 1761 (shown below) while Python 3.12 is installed.

Error 1761: Open Python Session in PythonNode_AddTwoDoubles.vi

Figure 1. Error 1761 returned by Open Python Session in PythonNode_AddTwoDoubles.vi.

Figure 2. LabVIEW shipping example, PythonNode_AddTwoDoubles.vi

 

 
 

Solution

1. Open subVI (with red bracket) used within the shipping example.
2. Locate the Python Version Enum/type definition. Add a new Enum entry for 3.12.
3. Update the Case Structure inside the subVI to include a new case for Version 3.12.
  • Duplicate the logic from the Python 3.10 case.
  • Ensure the Python path selection logic correctly maps to Python 3.12.
Figure 3. Added Python 3.12 to Enum and its case in subVI.
 
4. Save the updated type definition so all linked VIs are refreshed.
5. Confirm that both main VI and subVI now reference Python 3.12.
6. Run the example again—the Python Node should execute without errors.
Figure 4. PythonNode_AddTwoDoubles.vi executes without error using Python 3.12.

Additional Information

Although Python 3.12 is selected in the main VI, LabVIEW still loads an older Python version. This happens because the subVI’s Python Version Enum does not include Python 3.12 by default. As a result, subVI continues to use its default value, Python 3.6, causing LabVIEW to attempt to launch Python 3.6 instead of Python 3.12. This leads to Error 1761 when Python 3.6 is not found on the system.
Figure 5. Python version 3.6 is set as default.

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