Internal Warning when Upgrading to NI-DAQmx 18.0 or 18.1 with FieldDAQ

Updated May 31, 2023

Reported In


  • Current Input Device for FieldDAQ
  • Voltage Input Device for FieldDAQ


  • Measurement & Automation Explorer (MAX)


  • NI-DAQmx 18.0
  • NI-DAQmx 18.1

Issue Details

After I upgraded my version of NI-DAQmx to version 18.0 or 18.1, I can no longer use NI Measurement & Automation Explorer (NI MAX).  When I try to open NI MAX, I get an unexpected internal warning:

NI MAX has detected an unexpected internal warning, Visit and enter the info code MAXKnownException for more information.

When I close the warning dialog, nothing is populated into NI MAX, and I cannot select any options from the dropdown menus at the top of the application.


There is a Known Issue where having a FieldDAQ device in your NI MAX configuration during an upgrade to DAQmx 18.0 or 18.1 will cause your MAX database to become corrupted. 
To avoid this issue, complete the following steps before upgrading:
  1. Export your MAX Configuration prior to upgrade.
  2. Remove all FieldDAQ devices from the system (since they are network devices, you may need to power them down or disconnect them from the network)
  3. Upgrade DAQmx with no FieldDAQ devices in your system.
  4. Import your MAX Configuration after the upgrade is complete.
If you have already encountered this issue, you may be unable to use the “Reset MAX Configuration Data” menu option in NI MAX.  Follow the steps in How Can I Reset the MAX Database Without Opening NI MAX? to reset the database without using the menu option in NI MAX.


Additional Information

Once corrupted, the NI MAX configuration data will no longer be accessible and will be lost.  National Instruments recommends that you regularly export your NI MAX database to a backup file if you are using features such as Global Virtual Channels or NI MAX-based NI-DAQmx Tasks that rely on the database for a significant amount of configuration storage, to avoid losing valuable information if corruption occurs.