Load in multiple MATLAB files and extract 51st row

Why does my code below not work? I want to read in all the files of a certain type which works. But I want to create a matrix of the 51st row of each file. Note that in the files, there is a single header row.

clear
clear all
clc
projectdirectory = 'C:/Path/';
dinfo = dir( fullfile(projectdirectory, 'msd.*.data') );
N = length(dinfo);
row51 = zeros(N, 2);
for K = 1 : N
  filename = fullfile(projectdirectory, dinfo(K).name);
  fid = fopen(filename, 'rt');
  row51(K,:) = cell2mat( textscan(fid, '%f%f', 50, 'headerlines', 1, 'collectoutput', true) );
  fclose(fid);
end

[Walter Roberson]

Duplicate question answered at https://www.mathworks.com/matlabcentral/answers/415189-load-in-multiple-text-files-and-store-data-in-a-matrix#comment_601014