Are you trying to edit using Go 4? Just guessing here but it might be a RAM issue. Turn off all other apps and delete or move pictures, video, or other un-needed items to free up more RAM and try again.
I think you are likely correct. I determined that the sequence was shot in 4k. It was re-shot in 720 and sailed through processing.
At this point my camera is much more capable than my computing. More capable than my needs, truth be told.
Thank you for your reply!