by Andre Figueiredo.
Ok...I was wrong...Ray Morris help me at
https://tracker.moodle.org/browse/MDL-42639
If you have the same problem, verify if the following permissions are enabled to your Web Service Group:
moodle/user:viewhiddendetails, moodle/course:useremail, moodle/user:update, moodle/site:viewuseridentity
Thanks,