Autodesk Inventor, working with .NET Framework, previously allowed add-ins to use NuGet package/assembly versions that differed from those bundled with Inventor. However, with Autodesk Inventor 2025-2026 and the framework upgrade to .NET 8, this no longer worked out of the box and caused version conflicts. Autodesk recently released Inventor 2027, using .NET 10, with built-in assembly isolation to address this.
This article shows how to use that built-in isolation, using AssemblyLoadContext, to load an add-in and its dependencies into a separate container and avoid version clashes
A full sample application is available on GitHub. This repo combines the workflows for Inventor 2023-2024 (.NET Framework 4.8), Inventor 2025–2026 (.NET 8), and Inventor 2027 (.NET 10 with built-in isolation)
- It's the runtime's provider for locating and loading dependencies. Whenever a dependency is loaded, an AssemblyLoadContext instance is invoked to locate it.
AssemblyLoadContext provides a service of locating, loading, and caching managed assemblies and other dependencies.
To support dynamic code loading and unloading, it creates an isolated context for loading code and its dependencies in their own AssemblyLoadContext instance.
How to update the add-in?
Update Addin (.addin) File
- Add the
<UseInventorAssemblyContext> property set to 0 (zero).
<?xml version="1.0" encoding="utf-8"?>
<Addin Type="Standard">
<ClassId>{YOUR-GUID-HERE}</ClassId>
<ClientId>{YOUR-GUID-HERE}</ClientId>
<DisplayName>IsolatedInventorAddin</DisplayName>
<Description>IsolatedInventorAddin</Description>
<Assembly>IsolatedInventorAddin.dll</Assembly>
<!--Created for Autodesk Inventor 2027+, version 31.0-->
<SupportedSoftwareVersionGreaterThan>30..</SupportedSoftwareVersionGreaterThan>
<LoadOnStartUp>1</LoadOnStartUp>
<Hidden>0</Hidden>
<UseInventorAssemblyContext>0</UseInventorAssemblyContext>
</Addin>
Notes
The <UseInventorAssemblyContext> property is backwards compatible, as it is ignored and does not break when included in earlier Inventor versions.
With the change to <Addin Type="Plugin">, this add-in format is compatible and works as an AppBundle with the Automation API.
References
