Error Code " Struct contents reference from a non-struct array object."

% shear strain 10A_4_4_55+2_4 right cell
clc;
clear;
fileNameArray = dir('*.dat');
for i = 1:50
    datStruct = importdata(fileNameArray(i).name);
    a1 (:,i)= datStruct.data(1173,:);
    
    a2 (:,i)= datStruct.data(1175,:);
    
    a3 (:,i)= datStruct.data(1167,:);
    
    a4 (:,i)= datStruct.data(1181,:);
    a5 (:,i)= datStruct.data(1197,:);
    a6 (:,i)= datStruct.data(1213,:);
    
    a7 (:,i)= datStruct.data(1250,:);
    
    a8 (:,i)= datStruct.data(1309,:);
    
    a9 (:,i)= datStruct.data(1369,:);
    
    a10 (:,i)= datStruct.data(1425,:);
    a11 (:,i)= datStruct.data(1448,:);
    a12 (:,i)= datStruct.data(1469,:);
    
    a13 (:,i)= datStruct.data(1478,:);
    
    a14 (:,i)= datStruct.data(1476,:);
    a15 (:,i)= datStruct.data(1474,:);
    
    a16 (:,i)= datStruct.data(1445,:);
    
    a17 (:,i)= datStruct.data(1410,:);
    a18 (:,i)= datStruct.data(1372,:);
    a19 (:,i)= datStruct.data(1311,:);
    
    a20 (:,i)= datStruct.data(1233,:);
end;

Please can you help me correct this code. It gives "Struct contents reference from a non-struct array object."

Thanks.

[Adam Danz]

Could you provide the full copy-pasted error message and tell us what line is causing the error? It would also be helpful to see the variable values associated with that line.

Is this line below producing a structure?

datStruct = importdata(fileNameArray(i).name);

[David Clement]

The line bellow is producing the error

datStruct = importdata(fileNameArray(i).name);

[Adam Danz]

David Clement's answer moved here as a comment.

The line below is producing the error

datStruct = importdata(fileNameArray(i).name);

[Adam Danz]

What is the value of

fileNameArray 
% and
fileNameArray(i).name

?

Is this happening on the first loop (i=1)?