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Troubleshooting Common Problems

Last updated: 16 Oct 2026 6 min read

Most problems in an edit come down to a handful of causes: media that isn't where Lightworks expects, a setting that doesn't match the material, or a system under strain. This article collects the common symptoms and points to the fix.

Media problems

  • Clips show as offline - the source files have moved, been renamed, or their drive isn't connected. Reconnect the drive or relink the media (see Media management).
  • Import fails or a file won't play - the format may need conversion; some formats are automatically converted on import. Check the file plays outside Lightworks, then see Importing media.
  • Audio drifts out of sync on phone footage - classic variable frame rate. Enable Apply VFR correction in the project's video settings (see Media formats and technical settings).

Playback problems

  • Stuttering playback - work through the triage in Performance optimisation: proxies for heavy media, background tasks, disk space, GPU precision.
  • Black viewer but audio plays - check the track monitoring buttons in the track headers; a hidden or unmonitored video track is the usual cause (see Sequences and timelines).
  • No sound - check track mutes and solos in the mixer, then the audio output device in Settings (see The audio mixer).

Editing surprises

  • A keyboard edit affects the wrong tracks - check the Track Target buttons in the track headers. With none lit, a keyboard edit uses every track and a trim key trims the top clip under the playhead and its audio; with some lit, only those tracks are used. Targets you set for an earlier edit still apply, so Shift+click any Track Target to clear them. Using the mouse is different: clicking a clip, the start or end of a clip, or the cut between two clips, or using a clip's right-click menu, already says which clip you mean, so the targets have no say (see Trimming).
  • Video and audio out of step after editing - you've moved one without the other. Switch Clip Link on so they travel together, take care when you leave tracks behind - with a lock, or with Alt - and watch the timeline's sync indicators to fix any offset (see Editing audio in the timeline).
  • Video and audio don't move together - they may not be linked. Material laid in together is linked automatically, but a clip that was split leaves its second half unlinked, and material brought in separately was never linked at all. Select both and use Link (see Selecting and moving material).
  • Only some tracks moved - a locked track never moves, and nor do tracks left behind with Alt+click on a Track Target, or every untargeted track when Sync is off with Only Target Tracks Ripple chosen. The amber Track Sync strips in the track headers show which tracks will stay in sync: during a trim, a dark strip marks a track that will not.
  • A gap won't close - Delete gap across all tracks is greyed out because another track has material across the gap, so closing it would drag that track out of step. To take the black out on that one track, use Delete black segment instead (see Basic editing).
  • A track won't let me do anything - it's locked. A locked track takes no edit, no trim and no cut, and its levels and fades can't be dragged either. Unlock it in the track header (see Sequences and timelines).
  • Trimming the end of the sequence appears to do nothing - a sequence is as long as its longest track, so trimming one track's tail while another still reaches the end holds the length and pads the trimmed track back out. Trim the tail on every track to shorten the sequence itself (see Trimming).
  • I can move a clip but not trim it - it is too narrow to aim at. Below about a track row's width there is no centre left to grab, so the mouse treats the whole segment as its middle. Zoom in, or trim it from the keyboard - the keys and the menus are unaffected (see Trimming).
  • A track stopped being held in sync part-way through a trim - Lightworks keeps the other tracks in step by unjoining them where the change is hidden - in black, or under the clip you are trimming. Rejoining one of those takes that track out of sync for the rest of the trim, and its amber sync strip goes dark to show it. Click black on that track to keep it in sync again (see Trimming).
  • A trim took media off a track I did not trim - the track had no black to take up the change, such as a continuous music clip with no gap nearby, so it gave up media at the trim point to stay in step. Trim back and the media comes back. To leave a track where it is instead, lock it, or unjoin something on that track yourself before you trim - black, or the start or end of a clip (see Trimming).
  • Delete leaves black instead of closing up - a track being kept in sync has no black to give up across that range, so closing up would push it out of step. Lightworks says so. Lock that track to leave it behind, or target it too so the delete takes the same range from it (see Basic editing).
  • A transition won't go in - there isn't enough spare material either side of the cut (see Video transitions and fades).
  • Something unexpected happened - undo is deep; step back with Ctrl/Cmd+Z and try again (see Basic editing).

Export problems

Application problems

  • Lightworks closed unexpectedly - on the next launch you may be offered the chance to upload logs for analysis; sequences are saved continuously, so your work is preserved. Restart and reopen the project.
  • A project won't open, or opens somewhere unhelpful - hold Shift while starting Lightworks to go straight to the Project Browser instead of reopening the last project.
  • A licence feature seems missing - check the Settings menu's licence information to confirm what your plan includes (see Application preferences).

When to reach for help

If a problem persists, capture the details - what you did, what happened, the media format involved - and ask on the Lightworks forum, or raise a support ticket through the user portal. The version number and system information from the Settings menu help enormously.

Tip: The vast majority of "Lightworks is broken" moments are a hidden track, an untargeted track, or offline media. Check those three before anything else.

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