I can't find anything like this in the threads. Apologies if there's already a solution out there. I can relink the missing files fine. But I'm wondering if anyone else has seen this:
I shutdown FCPX normally and ejected my external drive before removing it w/o a problem, but when I launched FCPX later, almost all of the clips in one particular Event folder now have the File Missing warning. When I look at Info under the Inspector, the location field is set to a very large fcpbundle file (which I never noticed before in the root of my external drive) instead of the original clip file which is in the same folder it always was.
Also, when I launched FCPX, to open up a bunch of old projects and clips, I had to go open up that same fcpbundle file thru File>Open Library. Never had to do that before.