Error -1073807346: Given Session or Object Reference Invalid in NI VISA

Updated Jan 23, 2020

Reported In


  • LabVIEW
  • Measurement & Automation Explorer (MAX)



Issue Details

When I attempt to open a new VISA session to my instrument or use an existing session, I receive Error – 1073807346 VISA: (Hex 0xBFFF000E) The given session or object reference is invalid. 

How can I resolve this issue?


This error can happen for a number of reasons:
  • Missing driver: Install the correct driver and version for your hardware. For NI hardware, this information can be found under Supported Devices in the driver version's readme.​​​​​​
  • Incorrect Addressing: Verify that you are addressing your instrument correctly.
    • Check the resourcing in: 
      • Windows: NI MAX on the main configuration page (Settings) of your VISA resource
      • Mac/Linux: NI-VISA Configuration utility
      • If you are currently using VISA Alias, try using the VISA Resource Name
        • For example: using the Resource Name, ​ASRL3::INSTR, instead of the Alias, "COM3"
  • Device Not Powered On: Verify that your device is connected correctly and powered.
  • VISA Session Was Previously Closed: This error can also occur if the VISA session was unexpectedly closed during communication. The most common case in which this can happen is if the VISA resource is stored in a global variable. Disabling the Automatically Close VISA Sessions option can prevent the error:​​​
    1. Select Tools » Options to display the Options dialog box. 
    2. Select Environment from the Category list.
    3. Uncheck the Automatically Close VISA Sessions checkbox
    4. Select OK
    Note: If you disable this option, then make sure you are calling VISA Close when you are finished communicating with the device.

Additional Information

The Automatically Close VISA Sessions option allows open VISA sessions to close automatically when the top-level VI goes idle. This option helps you avoid potential problems the next time you run the VI. As a result, when you try to access that VISA session using a global variable, you can get an invalid VISA session error if the option is enabled.