Warning - Orphan Block Files
From Audacity Development Manual
Block files: Audacity stores the audio data in multiple short sections or block files (normally six seconds long) for details please see Structure of an Audacity project.
This warning message will be shown when you attempt to open an Audacity project which has audio data missing for some reason.
The warning dialog in project context
The log file
Peter 29Dec19: the raw out of context warning dialog - but I think I prefer the in-context one
