Imported about 50% of users from master site

OOPS: I just saw this https://premium.wpmudev.org/forums/topic/user-sync-problem-with-synchronization#post-124226 and will post my question to that thread instead.
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Your plugin is very promising.

On the first pass, it imported about 50% of the users from the master site to the sub site. Is there anything that might be blocking the sync of the rest?

Thanks!

Teresa