Traceback (most recent call last):
  File "/usr/sbin/ufw", line 1362, in <module>
    (action, rule, type, dryrun) = process_args()
  File "/usr/sbin/ufw", line 178, in process_args
    if valid_address(saddr, True):
  File "/usr/sbin/ufw", line 304, in valid_address
    if int(net[1]) < 0 or int(net[1]) > 128:
ValueError: invalid literal for int() with base 10: '255.255.255.0'