Hi Maarten
Thanks for writing this code; it is a great bit of software.
I am having problems with burning DVDs from my MacBook Pro (16" 2019) running macOS Catalina (10.15.4). It burns CDs fine but I have now tried three [external] hard-drives all with the same outcome. I am using DVD-R discs and it starts writing the DVD and almost immediately goes to "finalising" and ends with a failure. I have successfully burned each of these files onto siilar discs using Burn on my 10-year old MacBok Pro mid-2010 running an older version of macOS.
I wondered whether it was a power issue but two of the burners are designed for USB C and the other, connected via a USB-2 adapter, has a separate power supply.
This has been frustrating; I have wasted at least a handfull of discs and sent one burner back as faulty althouygh it may not have been!
Any ideas?