With 3.07 .dash.m4v left behind

[Nick Payne]

I've had three instances since installing 3.07 where the download of a
programme finishes without any problems or errors indicated in the
console output, but as well as the mp4 file there is also a .dash.m4v
file of slightly smaller size. I assume this is meant to be deleted once
the conversion to mp4 has been completed, but this isn't happening
consistently.

OS is Windows 10 x64.

Nick