Cutsio Blog

Why Timeline is Not Rendering in Final Cut Pro

Direct solutions for fixing stuck background renders, failed manual renders, and corrupted cache files in Final Cut Pro.

A timeline is not rendering in Final Cut Pro typically because background render is paused, the hard drive is completely full, or a specific corrupted clip is halting the process.

Here are the direct methods to fix rendering issues in Final Cut Pro.

How do you force a manual render?

If the dotted line above your timeline won't disappear and playback is lagging, Final Cut Pro's automatic background rendering might be stuck or disabled.

To force a manual render:

  1. Select all the clips on your timeline (Cmd+A).
  2. Go to Modify > Render All (or press Ctrl+Shift+R).
  3. Open the Background Tasks window (the small circle with a checkmark in the top left corner next to the timecode).
  4. Watch the "Rendering" progress bar to ensure it is actively processing the files.

How do you fix a render stuck at a specific percentage?

If the manual render always freezes or crashes at the exact same percentage (e.g., 45%), there is a corrupted clip, transition, or effect at that exact spot on the timeline.

To fix a stuck render on a corrupted clip:

  1. Look at the dotted line above the timeline to see exactly where the render stopped.
  2. Find the clip or effect immediately after the rendered section.
  3. Delete the effect, transition, or title applied to that clip, or temporarily disable the clip by pressing V.
  4. Try rendering again. If it succeeds, the effect or clip you disabled was corrupted and needs to be replaced.

How do you fix a render failing due to full storage?

If Final Cut Pro immediately throws a "Share Failed" or "Render Failed" error, your Mac's hard drive has run out of space to store the massive temporary render files.

To fix rendering failures caused by full storage:

  1. Select the Library in the Browser.
  2. Go to File > Delete Generated Library Files.
  3. Check the box for Delete Render Files. Select All.
  4. Click OK. This clears out all the old, bloated render files from previous edits, freeing up hundreds of gigabytes of space.
  5. Attempt the render again.