Will not import media from card

I've been using FCPX for years and never had this happen. I'm trying to import some mp4 clips into an event from a memory card. I check the "copy media to the library", as usual. The first weirdness is that the background tasks don't kick-in, as if there is no transcoding going on. Then when I eject the card the clips turn into the famous red "missing camera" warnings. I learned from past experience to give Final Cut plenty of time for the import until I get the import complete/eject card message. None of this is happening, no matter how long I leave it for (I've deleted the event and retried several times). Thanks for any insights.

Couple of initial questions:
- What camera / file format?   *frame size, data rate, audio settings, etc.
- Did you modify the contents of the card in any way prior to import?

Follow-up question:
- How much free space is on the destination drive?

Anytime I have a grumpy card that gets stuck on import, the first thing I try is copying the whole file structure of the card over to my edit drive, into a folder named the same as the card, or something that I'll remember. 

I then import the media from the copied folder. Usually that solves import issues.

If not, there might be something else wrong with the files on the card. Sometimes putting it back in the camera, and recording an additional short video to it will close out the previous file properly and enable it to be read better.

And sometimes not. 

Other things I've tried, include using Adobe Premiere to injest the media. If you have something else that can read it, like AJA control room, you might have more luck.
www.aja.com/products/aja-control-room

Hope that helps.

Thanks for your responses. This one will go into the category of the mysterious. I eventually deleted the event but after making a new one, this time dragged/dropped the files from the card into it instead of using the import window. Now everything worked as normal. !?!

Did you try deleting your FCP prefs? Whenever mysterious things happen in FCP it's an easy thing to try. Hold command and option when launching FCP, then choose Delete Preferences... If you have custom share destinations you'll need to reimport them.

Another way is to use Digital Rebellion's Preference Manager to reload known good prefs.