Why did my timeline become "unrendered""

Client drive went back to agency.
Agency returns with drive.
Media not found.
Reset scratch disk.
Reconnected media.

Rendering as I type.

Now rendered.
Some clips in full timeline view show "red" media offline.
Zoom in and it goes away.

Delete the files in the folder, Thumbnail Cache Files.
FCP will write new files restoring the thumbnail in the video tracks.

Rui Barros
Editor Colorist Trainer
Lisbon, Portugal
RTP Post-Production
Apple Certified Trainer FCP 7
Apple Certified Pro FCP 7

Thank you