Failure to do this backup FreePBX 13

Failure to do this backup FreePBX 13
I have based FTP vsftpd that time use and not by problems
I then decided to efferruare backup copies of my FreePBX 13 of this FTP but unfortunately a mistake …

Initializing Backup 4
Backup Lock acquired!
Running pre-backup hooks …
Adding items …
Bulding manifest …
Creating backup …
Storing backup …
Whoops \ Exception \ ErrorException: ftp_connect () Expects parameter 2 to be long, string given in /var/www/html/admin/modules/backup/functions.inc/class.backup.php file on line 394
Stack trace:

  1. Whoops \ Exception \ ErrorException -> () /var/www/html/admin/modules/backup/functions.inc/class.backup.php:394
  2. Whoops \ Run-> handleError (): 0
  3. ftp_connect () /var/www/html/admin/modules/backup/functions.inc/class.backup.php:394
  4. FreePBX \ modules \ Backup \ BackupAssist> store backups () /var/www/html/admin/modules/backup/bin/backup.php:144

Fixed my fault
Iptable misconfigured and then gave error to attempt to access …