Did you added your own Google API key? Look at the help.
Check in YouTube if the id PLlQrg2sIO-EwKdqrUrs7MrDBJEMysskCp belongs to a playlist. Check the FAQ of the plugin or send error messages to support.
Rehman Sobhan is a noted Bangladeshi economist and freedom fighter. He was educated at St. Paul’s School, Darjeeling; Aitchison College, Lahore; and the University of Cambridge. He was one of the economists whose ideas influenced the 6-point programme of Bangabandhu Sheikh Mujibur Rahman, which became the basis for the struggle for self-rule for Banglades