topic Re: API uploaded .step file cannot be opened but locally uploaded .step file can because of mismatch in version. in Fusion API and Scripts Forum

API uploaded .step file cannot be opened but locally uploaded .step file can because of mismatch in version.

r_vanderheijdenR5T8S — Thu, 15 Jan 2026 13:22:33 GMT

I'm uploading .STEP files with the API from a web interface. When I try to open them locally using my Autodesk Fusion Client, I get this error:

Fusion can't open 4022.645.71281_AB-01.step v1, which was persisted by version 2701.0.7 with your current software version 2605.1.52.

However, I've downloaded the latest version of Fusion and can't download a newer version. I can't open the .STEP files. But when I upload the same file locally with the Fusion Client is does convert the .STEP correctly to .f3d and I'm able to work with it perfectly.

It looks like a mismatch of versions when uploading with the API vs Locally.

This was working on 14 January 2026 and broke on 15 January 2026.

Re: API uploaded .step file cannot be opened but locally uploaded .step file can because of mismatch in version.

BrianEkins — Thu, 15 Jan 2026 15:56:23 GMT

What exactly are you using to upload the files?

The version referenced in the error is being released next week, or is available now to Fusion Insiders. I don't know if someone updated the backend too early or if the interface you're using is a pre-production API and this is expected.

Re: API uploaded .step file cannot be opened but locally uploaded .step file can because of mismatch in version.

r_vanderheijdenR5T8S — Fri, 16 Jan 2026 07:00:57 GMT

Hello Brian,
I used this guide to upload files to the Fusion Cloud: https://aps.autodesk.com/en/docs/data/v2/tutorials/upload-file/

To be more precise I build an web application with HTML, CSS and Javascript. Here I use javascript fetch requests to upload the files to the cloud. I do that in the order of the tutorial.

Re: API uploaded .step file cannot be opened but locally uploaded .step file can because of mismatch in version.

r_vanderheijdenR5T8S — Thu, 22 Jan 2026 10:15:02 GMT

Hello Brian,

It seems like someone updated the backend to early again. It's on version 2701.0.7 but the latest normal Fusion version is on: 2606.1.22

I didn't want to open a new thread because of it's the same issue I'm having.

If there is any extra information you need, feel free to ask.