"The operation could not be completed An unknown error occurred (-16979)"
MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports)
High Sierra 10.13.6
For first time, used Quicktime to record "high" quality video file using Facetime built-in camera & mic.
Recording stopped around 13 minutes automatically due to lack of drive space.
Cannot save, export, or locate the file.
Unable to close QT, restart or power-down device without risk of deleting file.
Attempt exporting/sharing to a few listed locations with no success.