Error 1663 Occurred at Open Python Session in LabVIEW

Updated Oct 23, 2023

Reported In


  • LabVIEW



Issue Details

I want to open a Python session in LabVIEW but I get the error below:
Error 1663 occurred at Open Python Session in...

Possible reason(s):
LabVIEW: (Hex 0x67F) Unable to load the Python interpreter of the specified version. Ensure that you install the supported versions of Python, and the bitness of Python matches the bitness of LabVIEW that opens the Python session.

Error 1663 pop up from simple error handler


This error occurs when LabVIEW is unable to open a session for the specified version for the Python version input when calling the Open Python Session Function. In order to troubleshoot this issue please follow these
  • Make sure that the bitness of LabVIEW matches the Python version installed. For example, if you are using LabVIEW 32-bit, you are required to use the 32-version of Python.
  • Check that the version of Python being called is compatible with the version of LabVIEW you are using. In the following link, you can check compatibility between Python and LabVIEW versions: Integrating Python Code in LabVIEW. Although unsupported versions might work with the LabVIEW Python functions, NI recommends using supported versions of Python only.
  • By default, LabVIEW will use registry entries to find the installed python3.x interpreters. If there is an issue with the registry entries, try using the python path input terminal to specify the directory where Python is installed.
  • If you are looking to call Python installed with a virtual environment make sure you are using LabVIEW 2023 Q1 or later and that you are using the Open Virtual Environment Session VI instead of Open Python Session VI.