What is the error when: ''Index exceeds the number of array elements. Index must not exceed 225'' and how to fix it

The warning appears when I put this code, what should I do?

for i=1:m;

for j=1:n;

T(i,j)=T2(counter2);

counter2=counter2+1;

end

end

[Torsten]

T2 seems to be an array with 225 elements. You can't exceed this limit.

[ANA BATRES FERNANDEZ]

Thanks!