Error when using IExplorerUtil.UpdateFileProperties from within job processor extension - only in 2026

[stp44QQS]

Hi,

have a issue with using IExplorerUtil.UpdateFileProperties from within an job processor extension in 2026. The exact same code works fine in all previous releases (2021-2025).

When the line for IExplorerUtil.UpdateFileProperties runs i first get an pop up error dialog from the job processor like below.

and the exception thrown looks like this from within visual studio. 

[Markus.Koechl]

@gbadziura : I am not sure that I got your feedback correctly.
I successfully tested Update 1 against two scenarios:

1) A console application using .NET48 (console apps need to continue consuming legacy .NET 48 libraries of the SDK) - failed.

1.1) A standalone application using .NET 8 (the matching platform targeting 2026) - success

2) A custom job extension consuming .NET8 (the matching platform targeting 2026) - success

Both performed the same task, updating the part number property of a test file.

What is working in your environments and what does run into an issue?

[gbadziura]

@Markus.Koechl :  

Hi Markus
I have built a solution that contains two projects. One is a console example project for updating properties with the Framework 4.8 SDK DLLs, and the other is a console project .netcore 8 for the corresponding .net core SDK DLLs.
The code is almost identical. However, an error occurs under 4.8 (ExplorerLoader.LoadExplorerUtil returns null), but it works under 8.0.
By the way, the 4.8 code worked fine under 2025. So either something has changed here that I haven't taken into account, or there is still a bug.
However, everything seems to be working again under .netcore 8.

I have attached my solution as a zip file. I would be grateful for any information about what is wrong.

I hope I have explained this clearly.

Best regards
Gerhard

[JanInventor]

Thanks. I did try to get it running, but without succes. I also run in to problems with your example; I got a 'boudn to source control warning. 
This is the only line of code in Vault 2026 that gives errors. It was working fine in Vault 2023.
I did have split the the publisher in two parts, a VB application to debug the code and for special actions. The second part is the real publisher where I copy the code in.
The publisher is working, but the application does not. Considered it was working before, it must be a bug.

I did try to migrate to .Core but I did get countless errors. 

[Markus.Koechl]

@gbadziura, @JanInventor: Unfortunately, I had to correct my answer given weeks before. Upon reviewing the test machine/dev environment, I realized I had two successful scenarios but also failed with the legacy one using .NET 4.8. Vault development confirmed my interpretation that IExplorerUtils are a subset of the current installed Vault Client (consuming binaries). Therefore, this specific API is bound to the .NET framework of the respective client: .NET 4.8 for 2025 and before, .NET 8 for 2026.x.

[JanInventor]

I did finaly managed to migrate to .Net 8.0. Now the code does work.

[Markus.Koechl]

Thank you, @JanInventor, for your feedback. Glad to get the confirmation.

[omar_semenzato]

I also update to 2026.1 and then solved the problem. Thanks a lot.

[omar_semenzato]

I also update to 2026.1 and then I solved the problem in our addin. Thanks a lot.