I have the same error as @mr_gholam I fixed this by going into the binhex-get-iplayer docker console (click the docker, click console), typing cd to go to the root, then nano start.sh
There's two lines about halfway down the page as it opens the window that contains the lines below
/usr/bin/get_iplayer --profile-dir /config --get --nopurge --tv-quality="fhd,hd,sd,web,mobile" --file-prefix="${show}......etc.etc
Remove the --nopurge command from these two lines and restart the container, it will now run.
I don't know the purpose of the --nopurge command but it downloaded a couple of episodes of a show that was missing them for me.