This a rep:mixin node which is already checked in and protected. Why will you move it? Why wont you just create it simply before creating the user through useradmin.
See: https://adobe-consulting-services.github.io/acs-aem-commons/features/errorpagehandler.html check what's missing and then also attach the request and error log.
http://cq-ops.tumblr.com/post/23543240500/how-to-use-cqs-query-debugger-tool use this and will get all details and also http://aemcq5.blogspot.com/2014/11/cq5-querybuilder-simplified.html