PHP 5 Internal error about chr(255).chr(254).@mb_convert_encoding

[nitiphone2021]

Dear all,
According to I install old project about cakePHP and I make some report but get a error about Server Internal error
As I checked It's error about this code

try{

$excelContent = chr(255).chr(254).@mb_convert_encoding($excelContent, 'UTF-16LE', 'UTF-8');

} catch (Exception $e) {

echo 'Caught exception: ', $e->getMessage(), "\n";

}

Do you have any idea about this code? I try to catch the error but it's not work

Edited June 28, 2021 by nitiphone2021

[gw1500se]

Remove the error suppression character (@) and post the actual error.

[nitiphone2021]

Now It fixed by install mdstring extension. Thank you very much