Final Cut: Render issues with compound clips and frames

Final Cut not managing render files well, some clips cannot be rendered.

I recently completed a feature-length project with several "sections" handled with compound clips. I found problems getting clips rendered.

From the main project timeline with compound clips in it I could see several sections of "render lines", the dotted lines that show a file hasn't rendered. Using Render All does not fix it. Opening a compound clip and hitting Render All does nothing. Selecting all clips and using Render Selection doesn't always render everything either. Selecting one of the unrendered clips and Render Selection also didn't actually render anything. What I finally ha to do was make a small adjustment in the clip, force a new required render, Render Selection, then reverse my change and again Render Selection. That finally got the clip rendered correctly.

I had to do this many, many times, searching carefully through the main project timeline for render lines, opening the compound clip, adjust, render, de-adjust, render. Very much of a pain, and depended on me actually visually spotting the unrendered clips.

Another problem is that there were clips that mostly were rendered (or didn't require rendering), except for one small section a few seconds long. That, too, could not be just rendered. I had to make a change to the entire clip, render, unchange, re-render to fix it.

Last issue: certain clip sections that have a few frames that absolutely cannot be rendered at all. I found this is true if you have a clip that has been shot when a still camera flash fires, and you retime that clip. The retime demands a rendering, but the few frames of flash won't render at all. It's not a huge problem, but if you're scanning a project for render dots, these pop up too, and they can't be fixed.