error message when try to unblock the user

My Opigno site has been attacked by unauthorized user, and I have to lock it down, and Admin will unblock all the registered user manually, but one questions is, this unblock process did not work any more, neither can admin delete the garbage account. It has two different issues; cancel the account failed From admin menu, go to People, I find the list of the garbage account, check two of those user, then choose "Cancel the selected user account", it ask me for the choice, I choose to "delete the account and its content" , it try to cancel the account, but failed with this error message An error has occurred. Please continue to the error page An AJAX HTTP error occurred. HTTP Result Code: 500 Debugging information follows. Path: /batch?id=103&op=do StatusText: Service unavailable (with message) ResponseText: from log, it show me this error message Location http://tutordiy.com/batch?id=104&op=do Referrer http://tutordiy.com/batch?op=start&id=104 Exception: Error while getting the user information from Moxtra servers in opigno_moxtra_app_user_delete() (line 142 of /home/proflu5/public_html/tutordiy.com/profiles/opigno_lms/modules/opigno/opigno_moxtra_app/opigno_moxtra_app.module). unblock the account failed Error while getting the user information from Moxtra servers xWarning message The user will be blocked. Try again by unblocking this user. From the log, it show me this error message Location http://www.tutordiy.com/admin/reports/dblog Referrer http://www.tutordiy.com/admin/people Notice: Undefined index: drupal in update_requirements() (line 35 of /home/proflu5/public_html/tutordiy.com/modules/update/update.install). Really frustrate, and look for advice from the forum, I seems has no luck, most of my previous question has 0 answer.