This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.
The target name editor allows spaces and probably other special characters. We should lock this down as they're also used as folder names.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-30662 in the post.