Hi there,
It appears that if you have Onedrive or Dropbox* running backing up the folder you are running CL from, it CAN (not always) lead to the program freezing/locking. This occurs when the output file being locked when is being backed up, but CL wants to write/add to the file at the same time. This does not ALWAYS happen - but I've noticed it a few times on my machine at home, and found that switching off Onedrive seems to fix it. Its only recently become an issue, so may be due to a onedrive update.. who knows. Next time I make an update of the code, I'll look into the issue.
All the best,
Tom
*I've not tried it with Dropbox, so it might be fine - but I suspect it may be a problem for some cloud backup services etc..