Thanks Dave.
Upload failed once again.
Tried to upload to YouTube, Facebook and Google Photos using two computers and the same problem.
Have to assume the video file has become corrupted and being blocked, but not bad enough not to play on either computer.
Will redo it after I've added the "Cunning plan" item I mentioned in the video.
I do, however, have one 'in the can' waiting to be edited, about making a 5C collet tray/holder, so will do this first or try uploading a short clip of something first just to make sure the computers aren't playing silly whatsits.
Geoff – Bad night so day off