Error with featured post image

Hello! The featured images got the grey overlay with the error message (see below). Website address: http://xn--52-6kclgdduvexbryr.xn--80adxhks/category/%d0%b6%d0%b8%d0%b7%d0%bd%d1%8c-%d0%bd%d0%b0%d1%88%d0%b5%d0%b3%d0%be-%d0%b4%d0%be%d0%bc%d0%b0/ Warning : Printf(): Too Few Arguments In /Home/C22974/Xn--52-6kclgdduvexbryr.Xn--80adxhks/Docs/Wp-Content/Themes/Adonis/Inc/Template-Tags.Php On Line 20 Could you please advice how to fix this problem? Regards, Nick