Error -49 opWrErr File already open with write permission
Trash the preference files while application is NOT Running.
from Karsten Schlüter
Some users notice on exporting larger projects from within iMovie that this operation is aborted with an 'error -49'
This issue occours only on MacOs machines using 10.7x
try switching-off the Local Mobile Backup
in Terminal copy/paste
sudo tmutil disablelocal
Yours Bengt W
This is what we did to solve the problem (which actually had said it was error -50):
We went through and tried to see if all the clips in our sequence had its matching raw counterpart in the "raw clip bank". They did. We also made sure that the imported material was the same kind of media- nothing too odd. (It was all video, recorded with the same camera). We remembered that we had copied and pasted the same clip (from our timeline/storyboard sequence) and inserted again within our timeline/storyboard. After deleting the clips we had originally copied, we drug the same clip from the raw clip bank. This fixed the problem.
We think that some of the "format" information goes missing when a clip is copied and pasted again within the same timeline. Maybe it can't find the "original" source, being in the raw clip dock above/below the storyboard.
*Other answers said to turn off the time machine- The time machine was already off on my mac.
*Other answers said that the memory could have been too loaded- My mac isn't loaded with stuff.
*Other answers said to reset the computer- We still received the error afterwards.
Our computer had been on for over 14 hours; working on an 8 minute video that had numerous effects and shots.