I am attempting to export the video files from a non-copy-protected DVD produced by Kodak (contains home movies converted to video) using Toast Titanium 18 on macOS Catalina 10.15.7. The first file starts converting, gets to 5% completed, and then aborts with the message "Couldn't complete the last command because (ID=-50). Result Code = -50". I have tried placing the output folder on an external drive (SMB mounted) and on the Desktop; the failure is identical either way. The progress window asked me to ensure that my Mac does not go to sleep, and I dutifully adjusted the Energy Saver system preferences. But this error happens within a few minutes of starting the export, and the Mac certainly never went to sleep, so that's not the issue. I get one partially complete output file. The error is 100% repeatable. A search of these archives turns up no actionable information.
I have to say that, as a professional programmer and former manager of programmers, if any of my engineers ever wrote software that displayed such a cryptic error message, I'd have a few words with them. What was the last command? What (in *human* terms) was the program attempting to do? Error messages should give you a clue as to what happened and how to resolve it. The fact that the error messages is displayed alongside a cute graphic in a fancy box is insulting. Grumpf.