createThumbnail API Method Behavior Changed After Recent Fusion Update

[rhrymakNRUS7]

This topic was originally posted in the Fusion Support Forum: https://forums.autodesk.com/t5/fusion-support-forum/createthumbnail-api-method-behavior-changed-afte...

I'm duplicating the issue here just in case it helps provide more context or visibility: 

After the recent Fusion update, the createThumbnail API method is no longer behaving as expected. Visually, it now highlights the geometry of components in an unusual way, and the resulting thumbnails appear inconsistent or unrelated to the actual component being processed. Additionally, iterative API calls seem to produce incorrect outputs that do not match the intended component.

This issue was not present before the update and appears to be a regression.
Please investigate this as soon as possible, as it likely indicates a bug.

[BrianEkins]

To be clear, which versions are you talking about? There have been major releases in January and March, and one is coming in May. The May Insider builds are also available now. Between those, minor fixes were released. Do you know which version it was working on and which version it started showing problems? 

[rhrymakNRUS7]

I’m referencing update v.2602.0.71 (May 19, 2025), which seems to have introduced a regression. The issue was not present in build 2601.1.37, where everything functioned as expected.

[BrianEkins · Accepted solution]

I can reproduce the problem and have made sure a bug was filed. Hopefully, it's fixed soon.

[rhrymakNRUS7]

Got it — thank you for the quick response. I really appreciate it!

[adam.nagy]

It's supposed to have been fixed in v.2603.1.31 – August 5, 2025

[Closed-Loop-Bot]

We're happy to report this issue has been resolved. Update Fusion to the most recent version to apply the fix. If this update resolved your issue, feel free to click the "Accept Solution" button to help other community members find the answer more easily. If the issue persists after updating, don't hesitate to reach out to us by replying to this thread. We're here to help! Let us know if you need any further assistance!