update

src/components/studyStudent.vue

@@ -5266,7 +5266,7 @@
             class="switch_box"
             v-if="
               courseDetail.userid == userid ||
-              courseDetail.course_teacher.indexOf(userid) != -1
+              (courseDetail.course_teacher && courseDetail.course_teacher.indexOf(userid) != -1)
             "
           >
             <!-- v-if="courseDetail.userid == userid || courseDetail.course_teacher.indexOf(userid) != -1" -->