Reference
Updated
Troubleshooting
The app will not start
Section titled “The app will not start”Lumit requires a GPU for rendering. You need a GPU that supports D3D12, Vulkan, or Metal.
Windows shows “Windows protected your PC”
Section titled “Windows shows “Windows protected your PC””The build is not code-signed on Windows, so SmartScreen warns on first run. Choose More info → Run anyway. See Installation.
Media shows as missing
Section titled “Media shows as missing”The project stores a reference to the file’s path. If that file is moved or deleted, Lumit will be unable to find it and the asset reports it as missing.
To fix this, click the Relink button, and this allows you to locate the file to recover it. See Importing media.
Playback is slow, or quality drops while working
Section titled “Playback is slow, or quality drops while working”Under load, or while scrubbing values to try and provide realtime previews, Lumit may reduce quality. For smoother playback, lower the preview resolution and let the cache fill on a first pass. See Preview and playback.
Lumit is a compositor. If you have chosen to render every frame, Lumit will do so as efficiently as possible; unfortunately you will be limited by your own hardware, but where possible increase cache sizes to let Lumit reduce the need to render. Despite previews not always being realtime or taking time to render, Lumit aims to provide a responsive interface regardless of what’s rendering.
Does exporting look the same as what I see in the Viewer?
Section titled “Does exporting look the same as what I see in the Viewer?”It may not. Exporting allows you to change certain options, including resolution and frame rate. Despite this, export will always render at full quality. Any adjustments you’ve made to the Viewer, such as changing the preview resolution, exposure, displayed grids, etc. are not seen by the export. See Exporting.
“Could not check for updates”
Section titled ““Could not check for updates””The update check got no answer it could use. Where GitHub refused the request, the message names its answer instead, such as GitHub answered 403: GitHub answers 403 when its hourly limit for the address is used up. The line under Edit ▸ Settings ▸ General ▸ Updates ▸ This version keeps the last reason. See Installation.
A plugin is missing
Section titled “A plugin is missing”When the start-up scan turns a plugin away, Lumit writes the reasons to plugin-scan.txt,
beside plugins.json in Lumit’s data folder:
| Platform | Folder |
|---|---|
| Windows | %APPDATA%\Lumit\Lumit\data |
| macOS | ~/Library/Application Support/dev.Lumit.Lumit |
| Linux (Flatpak) | ~/.var/app/io.github.luminalmvm.Lumit/data/lumit |
See Plugins.
Disk space drops while plugins are in use
Section titled “Disk space drops while plugins are in use”Each OpenFX plugin bundle that renders keeps a frame file of about 512 MB,
lumit-ofx-*.ring, in the system temp folder. A bundle that is installed but not used
takes a few kilobytes. The files are deleted when Lumit closes.
“Extensions need Microsoft WebView2, which isn’t installed.”
Section titled ““Extensions need Microsoft WebView2, which isn’t installed.””On Windows, extension panels need the Microsoft WebView2 runtime. Get WebView2 opens Microsoft’s download page. See Extensions.
“This project is already open in another Lumit window”
Section titled ““This project is already open in another Lumit window””A project is open in one Lumit window at a time. Opening it again brings that window forward. Where the system does not allow that, this message shows instead, and the project already loaded stays.