[Bug]: Lightning (Beta) export fails on Linux — "Cannot read properties of undefined (reading '_resourceType')" (WebCodecs avc1.640033, 1080x1350@60); Legacy works

[michumichifu]

Describe the bug

Lightning (Beta) export fails immediately on Linux. Switching the export pipeline to Legacy with the same project and settings exports successfully, so this is specific to the Lightning (Beta) path on Linux.

Full error shown in the app:

Lightning (Beta) export failed. Reason: Cannot read properties of undefined (reading '_resourceType')
Platform: Linux
Requested backend mode: auto
Output: 1080x1350 @ 60 FPS
Renderer: webgpu
Encoder path: WebCodecs (avc1.640033/prefer-software/quality)
Breeze fallback: H.264 Annex B encoding is not supported at 1080x1350.
Suggested actions:

• Lightning is designed to work on macOS, Windows, and Linux, but the available encoder path depends on WebCodecs support, GPU drivers, and the bundled FFmpeg encoders.
• Check that the packaged FFmpeg build includes a compatible Breeze encoder path for Linux, plus libx264 as a software fallback.
• Linux Lightning exports can use WebCodecs when supported, or FFmpeg encoders such as libx264 and optional GPU paths depending on the distro build.

Export settings used

• Size: Original (resolved to 1080x1350, portrait 4:5)
• Encoding: High Quality
• FPS: 60
• Export pipeline: Lightning (Beta) → fails; Legacy → works

Expected behavior

Lightning (Beta) should export successfully on Linux, or cleanly fall back to a working encoder path (WebCodecs or libx264) instead of throwing Cannot read properties of undefined (reading '_resourceType').

To Reproduce

1. Open a project in the editor on Linux.
2. Set output to Original size, High Quality, 60 FPS (resolves to 1080x1350).
3. Export using Lightning (Beta) with backend mode auto.
4. Export fails immediately with the error above.
5. Switch the export pipeline to Legacy and re-export → succeeds.

Environment

• OS: Fedora Linux 44 (GNOME, Wayland; app runs under XWayland)
• GPU: Intel Iris Plus (Ice Lake, i5-10th gen)
• Recordly: v1.3.3 (Linux x64 AppImage)

Possibly related (macOS variant): #501.