hey,guys.i meet a problem again.
The detail problem is the following :

Account a1 = new Account(
        Name = 'aiao1',
        Phone = '+34543331',
        Industry = 'Energy',
        Site = '12' );
Account a2 = new Account(
        Name = 'aiao2',
        Phone = '+34543332',
        Industry = 'Energy',
        Site = '34');
Account a3 = new Account(
        Name = 'aiao3',
        Phone = '+34543333',
        Industry = 'Energy',
        Site = '56');
Account a4 = new Account(
        Name = 'aiao4',
        Phone = '+34543334',
        Industry = 'Energy',
        Site = '78');       



List<Account> a6 = new List<Account>();
    a6.add(a1);
    a6.add(a2);
    a6.add(a3);
    a6.add(a4);
    

try {
    insert a6;
}
catch (DMLException e) {
    trigger.new[0].addError(e.getDMLMessage(0));
    System.debug(' DML Exception: ' + e);
}

when i insert these data, it will trigger a process, and the process will Execute a Flow 


the flow will execute the  following :

it will create a record,and when the record created success,it will update a field .
when a insert less than 4 records, it will execute successly.
but when the records equal or greater than 4, i will meet a error.


so can everyboby help me to solve this ?
very thx.
yours sincely .