diff --git a/src/main/java/org/olat/modules/lecture/manager/LectureBlockDAO.java b/src/main/java/org/olat/modules/lecture/manager/LectureBlockDAO.java
index 2494b77fb239df880f5c7de9a61af405a0dffc5c..0b4e6a9f5c642bff81d33c0ff937c2ed3a0a5f76 100644
--- a/src/main/java/org/olat/modules/lecture/manager/LectureBlockDAO.java
+++ b/src/main/java/org/olat/modules/lecture/manager/LectureBlockDAO.java
@@ -42,6 +42,8 @@ import org.olat.core.commons.persistence.PersistenceHelper;
 import org.olat.core.commons.persistence.QueryBuilder;
 import org.olat.core.id.Identity;
 import org.olat.core.util.StringHelper;
+import org.olat.course.assessment.AssessmentMode;
+import org.olat.course.assessment.manager.AssessmentModeDAO;
 import org.olat.modules.curriculum.CurriculumElement;
 import org.olat.modules.curriculum.CurriculumRoles;
 import org.olat.modules.lecture.LectureBlock;
@@ -78,6 +80,8 @@ public class LectureBlockDAO {
 	private DB dbInstance;
 	@Autowired
 	private GroupDAO groupDao;
+	@Autowired
+	private AssessmentModeDAO assessmentModeDao;
 	
 	public LectureBlock createLectureBlock(RepositoryEntry entry) {
 		LectureBlockImpl block = new LectureBlockImpl();
@@ -126,6 +130,11 @@ public class LectureBlockDAO {
 		LectureBlock reloadedBlock = dbInstance.getCurrentEntityManager()
 			.getReference(LectureBlockImpl.class, lectureBlock.getKey());
 		
+		AssessmentMode assessmentMode = assessmentModeDao.getAssessmentModeByLecture(reloadedBlock);
+		if(assessmentMode != null) {
+			assessmentModeDao.delete(assessmentMode);
+		}
+		
 		//delete lecture block to group
 		String deleteToGroup = "delete from lectureblocktogroup blocktogroup where blocktogroup.lectureBlock.key=:lectureBlockKey";
 		int rows = dbInstance.getCurrentEntityManager()
diff --git a/src/main/java/org/olat/user/ToolsPrefsController.java b/src/main/java/org/olat/user/ToolsPrefsController.java
index 3002301b02faa02e302a8eff03cc40f96e035d75..47ca6973308deac1b03c295e70cb8a4f5e495840 100644
--- a/src/main/java/org/olat/user/ToolsPrefsController.java
+++ b/src/main/java/org/olat/user/ToolsPrefsController.java
@@ -20,9 +20,9 @@
 package org.olat.user;
 
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.olat.admin.user.tools.UserToolExtension;
 import org.olat.admin.user.tools.UserToolsModule;
@@ -71,15 +71,10 @@ public class ToolsPrefsController extends FormBasicController {
 		
 		if(enabled) {
 			Set<String> aToolSet = userToolsModule.getAvailableUserToolSet();
-			userTools = userToolsModule.getAllUserToolExtensions(ureq);
-			if(!aToolSet.isEmpty()) {
-				for(Iterator<UserToolExtension> it=userTools.iterator(); it.hasNext(); ) {
-					UserToolExtension userToolExt = it.next();
-					if(!aToolSet.contains(userToolExt.getUniqueExtensionID()) || userToolExt.isShortCutOnly()) {
-						it.remove();
-					}
-				}
-			}
+			List<UserToolExtension> userToolList = userToolsModule.getAllUserToolExtensions(ureq);
+			userTools = userToolList.stream()
+					.filter(tool -> (!tool.isShortCutOnly() && (aToolSet.isEmpty() || aToolSet.contains(tool.getUniqueExtensionID()))))
+					.collect(Collectors.toList());
 		} else {
 			userTools = Collections.emptyList();
 		}