After upgrading to 1.7.5 I have the same problem.
Concretely, this code is not working
[Youtube_Channel_Gallery feed="playlist" user="PL8F1A9C6916AFC872" videowidth="580" ratio="16x9" theme="light" color="white" autoplay="0" rel="0" showinfo="0" maxitems="16" thumbwidth="277" thumbratio="16x9" thumbcolumns="2" title="1" description="0" thumbnail_alignment="top" descriptionwordsnumber="6" link="1"]
