Stepchart creation failed!

invalid SM file: measure with a strange number of notes (20 notes at line 144), notes are: array(20) { [0]=> string(4) "1000" [1]=> string(4) "0100" [2]=> string(4) "0010" [3]=> string(4) "0001" [4]=> string(4) "1000" [5]=> string(4) "0100" [6]=> string(4) "1000" [7]=> string(4) "0100" [8]=> string(4) "0010" [9]=> string(4) "0001" [10]=> string(4) "0100" [11]=> string(4) "0010" [12]=> string(4) "1000" [13]=> string(4) "0001" [14]=> string(4) "1000" [15]=> string(4) "0001" [16]=> string(4) "0010" [17]=> string(4) "0100" [18]=> string(4) "1000" [19]=> string(4) "0001" }