iMovie error 2191: the solution
The iMovie error 2191 is an extremely "popular" error.
Apparrently many desperate iMovie-users run in to it every now and then.
Apple does not seem to (or wants to) provide an error list (?????)
Bad service of the richest company in the world !!! Shame on you Apple !
But the meaning of the error is that the system ran into a corrupted frame or selection
somewhere in the project, while it was trying to finalize your movie.
HOW TO TRACE THE CORRUPTED FRAME IN YOUR PROJECT ?
Simply select "Duplicate Project" and work with this one, thus saving your original work.
Start deleting large selecties of scenes on this duplicate version (don't touch your original)
and regularly start "Finalize Project" to see if the error code 2191 still pops up.
If it does, continue deleting more scenes until the error does not show anymore upon selecting
"Finalize Project". Then you know that the corrupted frame was somewhere in the last selection you deleted.
Press "undo delete selection" and work with this particular selection by deleting smaller parts of it, thus closing in the corrupted frame or scene. Once you nailed it down and know exactly which frame was bothering the system, go back to your original (untouched) movie, remove the sick frame and up you go, finalize your project.
Good luck and enjoy !!!!
Douwe van der Kooi - Holland
iMac, macOS 10.12