diff --git a/src/main/java/de/thm/arsnova/services/QuestionService.java b/src/main/java/de/thm/arsnova/services/QuestionService.java
index 6d411350f81186e302c2ddbc14e8b952b81d8c02..98b5b7de88452658752a978f332c7bdd2d7e2b94 100644
--- a/src/main/java/de/thm/arsnova/services/QuestionService.java
+++ b/src/main/java/de/thm/arsnova/services/QuestionService.java
@@ -617,6 +617,9 @@ public class QuestionService implements IQuestionService, ApplicationEventPublis
 		if (subjectSortOrder == null) {
 			subjectSortOrder = createSortOrder(session, "lecture", "");
 		}
+		if (subjectSortOrder == null) {
+			return null;
+		}
 		final User user = userService.getCurrentUser();
 		return getQuestionsBySortOrder(subjectSortOrder, session.isCreator(user));
 	}
@@ -641,6 +644,9 @@ public class QuestionService implements IQuestionService, ApplicationEventPublis
 		if (subjectSortOrder == null) {
 			subjectSortOrder = createSortOrder(session, "preparation", "");
 		}
+		if (subjectSortOrder == null) {
+			return null;
+		}
 		final User user = userService.getCurrentUser();
 		return getQuestionsBySortOrder(subjectSortOrder, session.isCreator(user));
 	}
@@ -910,6 +916,9 @@ public class QuestionService implements IQuestionService, ApplicationEventPublis
 		if ("".equals(subject)) {
 			SortOrder subjectSortOrder = new SortOrder();
 			subjectSortOrder.setSortOrder(databaseDao.getSubjects(session, questionVariant));
+			if (subjectSortOrder.getSortOrder() == null) {
+				return null;
+			}
 			subjectSortOrder.setSubject("");
 			subjectSortOrder.setSortType("alphabetical");
 			subjectSortOrder.setQuestionVariant(questionVariant);