I'm not sure I can help with the "OSSstatus error - 101", but just checked the specs for your Nikon D3200 (nice camera). Certain frame rates with Full HD video can pose problems for iMovie.
Among other settings, I noticed that the Nikon can record 1920 x 1080 50p (or 60p for NTSC countries). That's 50 progressive frames per second. iMovie has trouble with that Full HD frame rate, but can handle 1920 x 1080 50i - that's 50 interlaced fields per second, being 25 frames per second (interlaced video has 2 fields per frame).
So, it's possible that you recorded at 50p, hence the problem you are seeing. The best solution for you is to record 1920 x 1080 25p (25 progressive frames per second). That will work fine in iMovie and give excellent results. iMovie works best with progressive video.
It's not clear from your question whether you've already imported clips to iMovie, or whether you are just having problems when trying to play back or export the clips from iMovie. In offering advice here, I'm assuming that you are having trouble importing to iMovie.
If in fact the problem is as I've outlined (format/frame rate issue), there is a "fix" that will enable you to import the footage to iMovie. But it is fairly complicated. Here's a link to an excellent article by Ian Odgers that will take you through the steps involved: