Missing NationalInstruments.Common.dll Reference in Measurement Studio

Updated Apr 9, 2020

Reported In


  • Measurement Studio


  • NI-488.2
  • NI-DAQmx


Microsoft Visual Studio

Issue Details

NationalInstruments.Common.dll has an exclamation point next to it in my Visual Studio project. How do I fix this?


The exclamation point occurs because Visual Studio cannot find the NationalInstruments.Common.dll.

NationalInstruments.Common.dll could be located in one of the following directories:
C:\Program Files<(x86)>\National Instruments\<MeasurementStudioVS200X>\DotNET\Assemblies\Current where <MeasurementStudioVS200X> corresponds to your version of Visual Studio.
C:\Program Files<(x86)>\National Instruments\MeasurementStudio\DotNET\v4.x\AnyCPU

It should also be installed to the Global Assembly Cache (GAC) located in:

You should also find the other National Instruments driver DLLs (NationalInstruments.XXX.dll) from drivers installed on your computer located in these folders (e.g. NationalInstruments.NI4882.dll, NationalInstruments.DAQmx.dll, or NationalInstruments.VisaNS.dll).

You can use the Reference Manager in Visual Studio to find the newest version of the DLL registered in the GAC.  If you find the DLL there, you can see the path to where the DLL is on disk.

If the file is there and you still have the error, then make sure to add the references to the project. Do this by selecting Project >> Add Reference... >> Browse... >> Select NationalInstruments.Common.dll library. Make sure to also add the driver library (e.g. NationalInstruments.DAQmx.dll or NationalInstrument.4882.dll) in this manner and include the line of code that imports the libraries. See the shipping examples for this code. For example, if you are using NI-488.2 driver in Visual Basic, include Imports NationalInstruments.NI4882 at the top of the code under the other Imports calls.

If you do not see the NationalInstruments.Common.dll in these locations you will simply need to repair the NI Measurement Studio Common .NET Language Assemblies for the .NET Framework. To repair this software, follow these steps:
  1. Open the Control Panel.
  2. Open Add or Remove Programs.
  3. Find National Instruments Software and click Change.
  4. Find and highlight the NI Measurement Studio Common .NET Language Assemblies for the .NET Framework X.X under the NI Products section.
  5. Select the Repair button in order to reinstall any missing files.

Additional Information

If you are getting missing namespace compile errors In your .NET Project, please refer to Missing Namespace Errors In My .NET Project.