What would cause Project File corruption?

I recently worked on a project and my project file kept becoming corrupt. I couldn't figure out the reason so I just reinstalled everything to make my system clean. I haven't restarted the edits yet but I'm curious if there is anything I can avoid to keep things moving.

I have since moved my media to an external drive.

What are the main causes of project file corruption?

My system is:
27" iMac 3.4 GHz i7
1 TB Internal ATA
3 TB External (Partitioned - 1TB Time Machine, 2 TB Video/Media)
16GB RAM
AMD Radeon HD 6970M 2GB GDDR5

The system should be adequate, but I would remove your time machine backup from the drive that is acting as your scratch media drive. The OS sees this as different volumes, but just the same, a completely separate media drive would be better. Keep your projects and events on a drive other than your OS if possible.

File corruption can occur from a number of things, including faulty plugins or effects that aren't rendering properly in FCPX, unfamiliarity with the application itself to an extent, outdated versions of the OS and FCPX, bad preferences, a corrupt render file that remains in the project, etc.

Turn background rendering off in your preferences and only render if you need to see the full effect, transition or image. With it on, it may be trying to keep up with your editing and getting backed up.

After an edit session, try deleting unused render files from both the project and the events the project uses. This will keep the file clutter down and help to streamline your project.

Could be lots of other things, but if these tips don't help, let us know what project format and file codecs you're dealing with, and what you're doing in the way of color grading, layering effects, titles, etc.

Hey dgw,
Thanks for the tips. I am fairly new to editing but I have watched the Lynda.com training on how to use FCPX. Far from expert but better than a complete newbie.

Once I can afford another drive then I'll have one set for Time Machine.

I've taken your suggestion to turn off background rendering. That seems to speed up my editing. I will delete the unused render files to try to keep things clean.

For the current project that I've had trouble with the third party plugins I'm using are Neat Video, Magic Bullets Mojo and CineLook. The clip would have at most two of the three plugins dropped on top of it depending on the scene etc.

I've used some of the built in effects and this project isn't particularly long nor does it contain many layers. Most of it is the main timeline with a few cutaway shots stacked on top. The music beds, sound effects and other audio only go 3-4 layers deep at most.

Most of the footage I'm working with comes from a Canon T3i. Also in the mix is some footage from my iPhone using Filmic Pro and a friend's Nikon (can't remember the model). I've been transcoding in FCPX. It's not pro stuff but something to help me along the way to get there.

I started back into the project last night. I'm keeping my fingers crossed that it will still be okay later today when I get to work on it.