.net framework vs .NET 8 (with winform)

[foreverkmsjeh]

I am currently using version 2024 and using an external program developed with .NET (Winform).

I'm trying to update to a new version, but I saw that the .NET version that will be applied from version 2025 has changed from framework to .NET.

So I installed 2026 additionally on my desktop and tried to apply external programs developed for 2024 and it ran without any problem.(I didn't change the version of Autodesk.Inventor.Interop either.)

Finally, my questions are as follows:

1) Will the 2025/2026 versions be able to use external programs developed with .net framework 4.x.x without any problems?

2) If so, are there functions such as Add-ins that require the .NET 8 version?

[bradeneuropeArthur · Accepted solution]

I have seen that most of the normal addins that are older and created with an older framework still load in Inventor 2025 and after. the case is, for what I have seen, that if you use forms in the add-in it must be converted to .net8.

[liminma8458]

"forms in the add-in it must be converted to .net8"? really? I have a lot of forms in my addins development in net framework 4.7. They all work well in Inventor 2026

[juergengross]

Yes, the most problem will be to get the document reference, as .net will not support the previous function

Marshal.GetActiveObject("Inventor.Application")

in net framework 4.7.

It is creasy, that inventor has not updated the own interface to support the correct document reference as Office product have done.

Thany you autodesk for your great non performance.