RID Cycling fails

[pwn-star]

[] Checking for usernames. This may take a bit...
[] Example command that will run: python2 /home/tester/Documents/icebreaker/submodules/ridenum/ridenum.py 10.3.10.43 500 50000 | tee -a logs/ridenum.log
Traceback (most recent call last):
File "./icebreaker.py", line 1602, in
main(report, args)
File "./icebreaker.py", line 1538, in main
prev_creds, prev_users, domains = smb_reverse_brute(loop, hosts, args, passwords, prev_creds, prev_users, DCs)
File "./icebreaker.py", line 618, in smb_reverse_brute
ip_users, prev_users = get_usernames(ridenum_output, prev_users)
File "./icebreaker.py", line 449, in get_usernames
out_lines = host.splitlines()
AttributeError: 'NoneType' object has no attribute 'splitlines'

[pwn-star]

output from ridenum.log:

[] Finished dumping users, saved to 10.3.10.43_users.txt.
[] Attempting lsaquery first...This will enumerate the base domain SID
[] Successfully enumerated base domain SID. Printing information:
Domain Name: WORKGROUP
Domain Sid: (NULL SID)
[] Moving on to extract via RID cycling attack..
[] Enumerating user accounts.. This could take a little while.
[] RIDENUM has finished enumerating user accounts...
[] Attempting lsaquery first...This will enumerate the base domain SID
[] Successfully enumerated base domain SID. Printing information:
Domain Name: WORKGROUP
Domain Sid: (NULL SID)
[] Moving on to extract via RID cycling attack..
[] Enumerating user accounts.. This could take a little while.
[] RIDENUM has finished enumerating user accounts...
[] Attempting lsaquery first...This will enumerate the base domain SID
[] Successfully enumerated base domain SID. Printing information:
Domain Name: WORKGROUP
Domain Sid: (NULL SID)
[] Moving on to extract via RID cycling attack..
[] Enumerating user accounts.. This could take a little while.
[] RIDENUM has finished enumerating user accounts...
[] Attempting lsaquery first...This will enumerate the base domain SID
[] Successfully enumerated base domain SID. Printing information:
Domain Name: KBOX
Domain Sid: (NULL SID)
[] Moving on to extract via RID cycling attack..
[] Enumerating user accounts.. This could take a little while.
[] RIDENUM has finished enumerating user accounts...
[] Attempting lsaquery first...This will enumerate the base domain SID
[] Successfully enumerated base domain SID. Printing information:
Domain Name: WORKGROUP
Domain Sid: (NULL SID)
[] Moving on to extract via RID cycling attack..
[] Enumerating user accounts.. This could take a little while.
[] RIDENUM has finished enumerating user accounts...