Hi,

In PHP 8.1 comparisons have changed if one of them is not a number.

Replace this function in frontaccounting/includes/db/audit_trail_db.inc:

function is_closed_trans($type, $trans_no) {

        $gl_seq = get_journal_number($type, $trans_no);
        if (is_numeric( $gl_seq )) {
                return  $gl_seq > 0;
        }
        else {
                return false;
        }
}