Hello there 
Alessandro shared the main.log file you sent to him, and I could see this in the recent messages in that log file:
[error] Error: connect ENOENT /var/run/docker.sock
and based on the information you provided (DK0006 / Couldn’t download docker containers) and that you’re using Mac OS., you may want to check and follow the solution suggested in this another thread here and here as well , that might help you to solve that DK0006 error issue on Mac.
Please let us know the results.
Cheers,
Agus