.

app/controllers/wechats_controller.rb

@@ -187,7 +187,7 @@ class WechatsController < ActionController::Base
 
   def join_class(content, user)
     cs = CoursesService.new
-    status = cs.join_course({invite_code: content.upcase.strip}, current_user)
+    status = cs.join_course({invite_code: content.upcase.strip}, user)
     logger.info status
     if status[:state] != 0
       raise CoursesService::JoinCourseError.message(status[:state])