18 troubleshooting

Troubleshooting

Start with a short reproducible example and the error/status text. Keep the saved composition and source files until the cause is understood.

Symptom	First checks
Compose library is empty	Heart a seed in Fine Tune/Explore, or start a guided recipe. Confirm which portable copy/data folder is open.
A seed stays still	Enable its saved profile; choose a supported preset/local motion; check source mode is not No source animation. Some grid-fit formulas need native parameter motion instead of a camera move.
A repeating animation jumps	Inspect across the effective cycle boundary. Use a loopable preset or match authored endpoints; Repeat/Ping-pong does not create new content or guarantee every arbitrary curve is seamless.
A parameter edit has no visible effect	Confirm Parameter target, source animation mode, formula support, interpolation, and the current preview interval. Re-render an invalidated preview.
Overlay disappears or dominates	Check layer order, opacity, blend, matte inversion/threshold, and key color. Overlay effects apply before keying. Base effects apply to the final composite.
Formula mix is unavailable	Both formulas must use the shared supported 3D mixer, both must use Main camera, and a B/C slot must be available. Other sources use overlay layers.
MP4 looks unlike Compose	Save the final draft; select that saved name; inspect queued names; match backend/aspect ratio/time; compare a retained PNG. Follow the Render checklist.
A composition cannot load intact	Read the named source/profile/asset error. Restore the correct library/assets from backup. Do not discard the damaged original or silently replace missing layers.
LUT missing after moving the app	Move the library together with its sibling composition-assets folder. Older external references may also need their original LUT. Re-save a valid older composition to capture its LUT into managed assets.
Preview looks blockier than final	Preview size and cached FPS are intentionally bounded. Increase preview size if needed; final export uses its own dimensions/FPS.
Preview render stops after switching tabs	Hiding Compose cancels unfinished preview work. Return and render the window again. This does not cancel a separate final Render job.
High memory or sluggish desktop	Lower simultaneous work before increasing resolution; reduce GPU concurrency, close unneeded live previews, and keep CPU headroom. Large layered frames and retained PNGs have real memory/disk costs.
GPU/encoder unavailable	Refresh hardware, inspect renderer availability and mappings, then test a short job. The HLSL rendering GPU, WebView2 GPU, and NVENC encoder route are not the same setting.
Procedural panel is blank	Verify WebView2, allow its initial load/compile to finish, inspect workspace diagnostics, and try a bundled starter. Imported shaders may require review and Compile on GPU.
First Generator Lab family activation is slow	A cold shader/driver cache can take longer than later selections. Wait for status/diagnostics; avoid repeatedly starting new heavy jobs during initialization.
Clip Studio has no usable source	Refresh Video library and check the tracked output folder. A complete retained PNG sequence is preferred; an incomplete sequence is not a valid complete clip.
Slow-motion playback looks stepped	Count unique source frames, not only export FPS. Export resampling can duplicate/drop frames; it does not synthesize detail.
Preview plan takes longer with scoring enabled	Optional CPU scoring renders small sample frames. Disable it for fast planning or constrain expensive families. It is a selection aid, not proof of artistic compatibility.
API connection refused / 401	Start the server and use its actual base URL / bearer token. Validate only checks JSON; it does not authenticate or start a server.
Retried render did not reuse PNGs	The render identity must match, including FPS and parameters. A changed job must rebuild incompatible frames.

Report a reproducible issue

Include the executable version/build, owning tab, composition/project name, renderer, enabled hardware, dimensions, FPS/duration, exact steps, and the first useful error from today's log. For a visual mismatch, include the same-time Compose preview and rendered frame. Keep tokens and unrelated personal paths out of a shared report.

Use Cancel in the owning workspace before force-stopping a process. Preserve data and output first; Files and recovery explains backup and restoration. Deleting the entire data folder is not a general repair.