Error codes
Meanings for the code: line in Copy for support. Paste that text into the site assistant.
The desktop app names failures with a short code. Copy for support on a queue row puts that on a code: line, plus stderr. Paste the whole text into the assistant — the Worker looks the code up. Do not attach the clip.
code: unknown means the engine exited before it emitted a named code. The assistant still classifies common stderr (CUDA OOM, disk full, missing encoder). If nothing matches, use Talk to a human.
See troubleshooting for preflight (VRAM, denoise fallback, Remaster CUDA).
Codes
cuda_oom
GPU ran out of memory for this recipe at this resolution. Close other GPU apps, then use the fix on the failed queue row: Switch to Export Ready (it upscales one frame at a time and fits smaller cards than Remaster), or Change recipe and re-run with a lower output resolution.
disk_full
The temp or output drive is full. Free space, or point Settings → Advanced → Storage → temp folder at a larger drive: Choose temp folder on the failed row opens it.
encoder_missing
FFmpeg lacks the encoder for that delivery format. Switch to H.264, or install a full FFmpeg and set its path in Settings.
corrupt_input
The source is missing, truncated, or not a format FFmpeg can decode. Confirm the path, play it elsewhere, remux to H.264 MP4 if needed.
ffmpeg_failed
An FFmpeg subprocess failed during extract, encode, or remux. Read the stderr tail. Try bundled FFmpeg and H.264 delivery.
scenedetect_unavailable
Detect cuts and split needs PySceneDetect. Use manual splits, or reinstall so the engine includes it.
backend_unavailable
That AI stage has no working backend, usually a model weight that is not downloaded. Settings → Advanced → Hardware → download missing weights, or turn the feature off for this run.
compare_source_missing
Before/after needs both files on disk. Restore the missing path or re-run the job.
compare_output_unwritable
Could not write the before/after video. Check free space and that nothing has the previous file open.
compare_font_missing
Burn-in needs the font bundled with the engine. Reinstall, or turn burn-in off if you only need the wipe.
framediff_source_missing
Review difference view is missing a before or after file. Restore the files and open Review again.
framediff_ffmpeg_failed
FFmpeg could not build the Review difference view. Confirm both files play, then retry Review.
engine_not_configured
No Python engine. Reinstall so the bundled engine is restored, then check Settings → Advanced → Engine.
engine_spawn_failed
The engine binary was found but did not run. Run Test engine in Settings → Advanced → Engine. Clear a bad Python override. Allow FrameLathe through antivirus / SmartScreen.
engine_argv_mismatch
App and engine are out of step. Update FrameLathe so they ship together.
vsr_torch_missing
Remaster needs PyTorch in the interpreter that is actually running. Settings → Advanced → Hardware → Download GPU engine (~2 GB). Use Export Ready on Vulkan/ncnn.
vsr_cuda_missing
Remaster needs CUDA torch, not a CPU wheel. Settings → Advanced → Hardware → Download GPU engine. Remaster needs an NVIDIA CUDA card.
vsr_weights_missing
RealBasicVSR checkpoints are not fetched with the other models. Settings → Advanced → Hardware → Download Remaster weights. Do not reinstall torch for this code.
sidecar_stale
Bundled engine does not match this build. Update FrameLathe.
gpu_busy_agent
An AI app connected under Settings → AI apps is rendering on this graphics card. One render runs at a time, so Start or the preview did not start anything and no clip failed. Start again when the app’s render finishes, or stop it under Rendering now in Settings → AI apps. The other way round, an AI app is told gpu_busy while the queue renders. See AI apps.
licence_required
Polish, preview samples, and Start need a licence bound to this machine. Paste the emailed key in Settings → Updates & licence. Activation is once; Start does not phone home. Import, plan, and thumbnails still work. No key yet? Buy one on the pricing page.
trt_cuda_missing
TensorRT build needs CUDA torch. Download the GPU engine, or skip TensorRT — upscale already runs on CUDA torch.
trt_build_ram
Not enough free system memory to build TensorRT. Close a browser and retry, or skip it. Nothing is wrong with the card or the download.
trt_not_installed
TensorRT for RTX is missing from this engine. Download the GPU add-on pack again, or skip TensorRT.
hub_model_licence_blocked
This Hub or imported model is blocked because the Hub licence filter is on, and the recorded licence string looks non-commercial, restricted, or missing. Clear the custom model on the row, pick a model the filter allows, or turn the filter off in Settings → Advanced → Model Hub. FrameLathe does not license Hub weights; the publisher’s terms still govern.
hub_slot_closed
This stage has no bring-your-own slot. Colorize runs first-party DDColor. Use the Upscale, Denoise, or Matting tab instead, or clear the custom model on the queue row.
sr_blank_output
The denoise or upscale model returned blank (flat black) frames for a clip that has picture, and did it again on the automatic retry, so the job stopped instead of delivering a black video as done. It has been intermittent. Re-run the job, and update the GPU driver if it repeats. If Export Ready keeps doing it, try Remaster, which runs on a different GPU engine.