File error on opening spreadsheet created with Spreadsheet::WriteExcel - excel

Question

I was using Spreadsheet::WriteExcel to create xls file using perl. When the range of spreadsheet increased, the Microsoft excel shows an alert before opening the file "File Error: Data may have been lost".
Please help me to solve this.
Here is the code
my $row = 2;
foreach my $sid(array of students objects)
{
my $s = $students->{$sid};
my $cc = 0;
my $wall = f1($x, $y, $z);#f1 is a method returns hash of arrays that have to write on excel having keys #key_array
foreach my $key (#key_array) {
my $t_row = $row;
my $i_c = 0;
my $t_col = 0;
my $m_row = $max_row;
while($m_row > 0){
$t_col = 3+($cc*7);
if($cc == 0){
$ws->write($t_row, 0,
[$s->{first_name}, $s->{last_name}, $s->{l_name}], $fmt_wrap
);
}
if(defined $wall->{$key}->[$i_c] ){
$ws->write($t_row, $t_col, $wall->{$key}->[$i_c], $fmt_wrap);
} else {
$ws->write($t_row, (3+$cc*7),["","","","","","",""], $fmt_wrap);
}
$t_row++;
$i_c++;
$m_row--;
}#while loop
$ws->write($t_row-1, 3+$company_format*$max_step,
[ (scalar keys %{$s->{videos}}), $s->{total_pageviews} ], $fmt
);
$cc++;
$t_row = 2;
}#foreach loop
$row+=$max_row;
}#foreach student array

Answer 1

I have found answer. In the code there was a line which write data into a cell multiple times. So i found that multiple write attempt to a particular cell can cause file corruption.