input file bug when required

Hello

with cf7 5.4 and cf7 grid layout 4.9.2 activated

Leaving the required file upload field blank generates the following table as input to the wpcf7_flat_join () function in the /plugins/contact-form-7/includes/functions.php file
bellow my test
array(13) {
[0]=>
string(8) “10.0.0.7”
[1]=>
int(36928)
[2]=>
string(20) “wpcf7-f1982-p1978-o1”
[3]=>
string(8) “aaaaaaaa”
[4]=>
string(12) “bbbbbbbbbbbb”
[5]=>
string(11) “ccccccccccc”
[6]=>
string(10) “dddddddddd”
[7]=>
string(12) “eeeeeeeeeeee”
[8]=>
string(11) “ux-designer”
[9]=>
string(0) “”
[10]=>
string(13) “fffffffffffff”
[11]=>
string(1) “1”
[12]=>
object(WP_Error)#9756 (3) {
[“errors”]=>
array(1) {
[“wpcf7_invalid_required”]=>
array(1) {
[0]=>
string(25) “Ce champ est obligatoire.”
}
}
[“error_data”]=>
array(0) {
}
[“additional_data”:protected]=>
array(0) {
}
}
}`
and the function is ko on the processing of array[12]=>
and the ajax call generates an error 500