Hi,
I just installed Populator on Latest Joomla 3.4.5 and Jomsocial 4.0.7.
When I try to create users I get this error:
Error
Jomsocial Populator : COM_COMMUNITY_FIELD_CONTAIN_IMPROPER_VALUES (Code : 0)[i]

so untill now it is useless.
Otherwise very useful idea for developers.
Thanks and regards