Error 0x80131515 When Loading an Assembly to TestStand From a Network Location

Updated May 18, 2022

Reported In


  • TestStand

Issue Details

I have a .NET assembly I wan to use as a code module in TestStand. This assembly is in a network location and when I try to load it I get an error message like this:

Could not load file or assembly file [  ] or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)
An attempt was made to load an assembly from a network location which would have caused the assembly to be sandboxed in previous versions of the .NET Framework. This release of the .NET Framework does not enable CAS policy by default, so this load may be dangerous. If this load is not intended to sandbox the assembly, please enable the loadFromRemoteSources switch. See for more information.


We recommend checking whether it is completely necessary to load the assembly from a remote location, since this could cause some security vulnerabilities on your system. If possible, place the assembly on a local directory on the machine running the test sequence. If you require to load the assembly from a network location follow these steps:

  1.          Go to the installation directory for TestStand:
  •     For 32 bit TestStand: C:\Program Files (x86)\National Instruments\TestStand 2019\Bin
  •   For 64 bit TestStand: C:\Program Files\National Instruments\TestStand 2019\Bin
  1.          Open SeqEdit.exe.config with a text editor (notepad for example). Create one if it does not exist.
  2.          Add the following line to the "runtime" section
    <loadFromRemoteSources enabled= "true"/>
  1. The file should look like below. Please refer to TestStand and .NET Framework Compatibility for the supported versions of NI TestStand with .NET
<?xml version="1.0"?>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2"/>
    <loadFromRemoteSources enabled= "true"/>
    <generatePublisherEvidence enabled="false"/>
  1. Save the file and restart TestStand.