Why can't i edit long clips i record with the Elgato Game Capture Card

So im trying to record gaming footage using the Elgato game capture for my gaming channel. Everything works out perfectly except when i try to edit the footage in final cut express. If i record a clip that is 30 seconds or less, i can throw the exported .m4v file into final cut no problem. But if the file is any longer than around 30 seconds then i cannot put the clip in final cut, it just wont import. If i drag the file to the timeline, nothing happens. I really need to figure this out, because the software itself is very easy to use and i really would like to use it. What do i do?