FCP has suddenly begun re-rendering projects on every launch

My FCP has started to act strange. When I open up a project, FCP starts to re-render the timeline (everything which is already rendered on the latest edit session). This has never happened before.

EDIT: It seems this re-render only occurs on my newer projects using 4K footage on a 1080 timeline. Even an old 1080-project with one single 4K shot recently inserted has begun to re-render on every relaunch of FCP, - not only the single 4K shot, but the whole timeline.

I use FCP vers 10.2.3.

Does anybody here have any idea what causes this?

Hey Frits,

Turn Background rendering OFF, delete all your Project render files and render manually. This should solve the issue.

It's better to always have Background Rendering disabled and only render when you really need to. This will prevent render file corruption issues (which is what you are seeing now), and it will save you loads of drive space.

- Ronny

Hi Ronny

Thanks. Well, in fact I already have stopped using bg-rendering since 3-4 month. As you recommended I have now deleted all renderfiles for all projects and it seemed to work in the first place, - but then things got even worse .
Suddenly the inspector window in all projects went empty except for the FCP defaults, meaning no color correction or other inserted effects were visible in the inspector. I had s suspicion that a certain project might be the reason as that one also kept "asking for" re-rendering though all renderfiles were deleted and re-rendered again.

Long story short: First I deleted the FCP-.pref-file. This did the trick, but as soon as I opened the said project everything went bananas again. So I removed the corrupted projectile, made new pref-files once more and now everything is back to normal.

PS.: The project with the corrupted file was finished two month ago so no really harm done here.

Clearly a corrupt project, and glad to hear you have found the solution. If you ever need to work on that project again, you can try to create a new Library and move the project over to the new Library. That usually does the trick.

- Ronny

I´l remember that, - thanks for your help.