Pieces of Clips won't render & cannot export without errors

I have two serious problems. I cannot get sections of clips in my timeline to render. I've even tried dumping all the render files for the project and re-rendering from scratch - same thing. Tiny pieces of a few clips won't render. I cannot afford to start over from scratch and I am really hoping someone can help me solve this problem.

My second problem is exporting. It never works with either of the projects I am working on. To be honest the only things I have ever gotten FCP X to export successfully were aprox. 1 min clips. I am so frustrated and disappointed with FCP X, I would ask Apple for a refund if I actually thought they would give me one. I cannot believe how bad this software is. It should have been the next version of iMovie.

In fact that's only one problem. As some parts of your clips won't render this means there is a problem with those clips, so it's normal your export will stop there.

What version of FCPX and OS are you running?
What are the clips that won't render? (Stills, graphics, video?)
Do you have any effects applied to the problematic clips? If so: which ones?

- Ronny

I've had a very similar problem with a project I was working on. I had a wedding ceremony that I have been editing, with four separate story lines (4 camera angles). A small section of one of the clips (shot at 30fps and slowed down to 24fps) wouldn't finish rendering. It stayed orange forever, never changed, and the GPU fans spun up to max speed. The progress indicator kept going from 0-100 forever. I let it just sit there (over an hour) in hopes it would finish rendering, but it never stopped. Infinite loop of sorts for sure.

The only fix I found to help was to find the exact clip in the event browser and replace the clip. Fortunately, that was the only clip that needed fixing and it was small (5 seconds).

The only thing I can think of that might have caused the problem is, I've been changing out video cards in my 2008 Mac Pro to see which ones worked best. No idea if this would have caused it.

Hope some of the details I've mentioned can help. Wish you the best because it can be very frustrating.