Bug 2420140

Summary: FBX exporter does not work
Product: [Fedora] Fedora Reporter: snuutti
Component: blenderAssignee: Luya Tshimbalanga <luya_tfz>
Status: ASSIGNED --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: unspecified    
Version: 43CC: code, design-devel, epel-packagers-sig, gang65, kitlith, luya_tfz, negativo17
Target Milestone: ---Keywords: Upstream
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Hardware: x86_64   
OS: Linux   
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Description Flags
FBX exporter traceback
none
Screenshot of error none

Description snuutti 2025-12-08 19:43:14 UTC
Blender's FBX export functionality no longer works after upgrading to Fedora 43. When attempting to export to the FBX format, an error popup is shown instead. This issue doesn't require a specific blender file to happen, it happens even with just the default unchanged scene. This happens on both of my machines, both with fresh Blender installations.

Reproducible: Always

Steps to Reproduce:
1. Open Blender
2. Go to File->Export->FBX
3. Click Export FBX
4. Notice the error popup
Actual Results:
A popup displaying a bunch of Python tracebacks is shown.

Expected Results:
Create the FBX file of the 3D model.

Comment 1 snuutti 2025-12-08 19:44:21 UTC
Created attachment 2118023 [details]
FBX exporter traceback

Comment 2 Luya Tshimbalanga 2025-12-09 03:30:24 UTC
I confirm the reproduction of the traceback which seems affecting all operating systems running version 5.0.0. according to upstream bug report:
https://projects.blender.org/blender/blender/issues/151290

Comment 3 Kitlith 2026-01-11 05:33:01 UTC
I suspect that the upstream bug report is not related. The upstream bug has a specific cause (can't export when in X state), with tracebacks of the form `AttributeError: 'NoneType' object has no attribute 'nodes'`. This bug produces tracebaks of the form `AttributeError: 'ExportFBX' object has no attribute 'path_mode'`, I can trigger this bug with the default blender scene, and it also causes the FBX export settings to be absent when you are selecting where to export to.

Workaround: I was able to export an FBX using Blender 5.0.0 from the flathub flatpak, instead of Blender 5.0.1 from the (non-flatpak) fedora package repository.

(This workaround is another reason why I suspect that this is not an upstream bug.)

Comment 4 Luya Tshimbalanga 2026-01-11 21:41:38 UTC
The bug also affected Windows version as highlighted on comment #2. Upstream provided a patch which resolved the issue.
The scratch build is available at the time of writing for testing:
https://koji.fedoraproject.org/koji/taskinfo?taskID=140999365

Comment 5 snuutti 2026-01-11 22:47:01 UTC
I tried the scratch build on my system but nothing's changed, I'm still getting the same list of errors.
I've also tested the latest Blender version 5.0.1 on Ubuntu 24.04 and Windows 10, and neither system has this issue which also makes me believe this is unrelated to the upstream bug.
The workaround of using the Blender flatpak won't work for me as my use case requires Blender's Python API.

Comment 6 Luya Tshimbalanga 2026-01-11 23:22:56 UTC
Could you show a screenshot of that error? Try to clean install Fedora Blender with https://bodhi.fedoraproject.org/updates/FEDORA-2026-71de399b02 and enable updates-testing repository.

Comment 7 Luya Tshimbalanga 2026-01-11 23:23:55 UTC
Note that version includes both MaterialX and manifold3d.

Comment 8 snuutti 2026-01-12 18:16:39 UTC
Created attachment 2121920 [details]
Screenshot of error

Comment 9 snuutti 2026-01-12 18:17:05 UTC
I've tried a clean install with the update, no difference.

Comment 10 Luya Tshimbalanga 2026-01-23 00:11:48 UTC
It turned out the issue is the compatibility between Blender Python API and Python 3.14. While it is possible to use Python 3.11, other python packaged componenet line numpy are built on Python 3.14 on both Fedora 43 and onward which increases the complexity of the maintenance.
Upstream is willing to address the issue as highlighted on https://projects.blender.org/blender/blender/issues/152809#issuecomment-1813202