Final Cut Pro X hangs when loading a project

Some of you may have experienced the beachball of death when FCPX tries to load a project and eventually resorted to force-quitting the app.

In most cases, the app hasn't hung at all but is just taking a really long time to open the project. If you leave it long enough (8-12 hours) it should eventually open. We recommend running our Project Repair tool to optimize the project file before doing this, as the optimization process lowers the file size and can shave off some loading time.

The reason it is taking so long is that the project has become too complex. A common cause of this is over-use of compound clips, especially compound clips inside multiclips. I have seen this lead to multi-gigabyte project files, even though the timeline was only a few minutes long.

Once the project opens successfully, begin the process of removing the compound clips. FCPX will hang for a short while whenever you try to do anything, but as you reduce the number of compound clips it will become more and more responsive.