diff --git a/src/main/java/org/olat/core/commons/services/vfs/ui/version/VFSTrashController.java b/src/main/java/org/olat/core/commons/services/vfs/ui/version/VFSTrashController.java
index 138f14c010fe440617cb3c4ee9f7d99edcffc25b..0c637c47bfadf63c1c27db295ac412157ae7da16 100644
--- a/src/main/java/org/olat/core/commons/services/vfs/ui/version/VFSTrashController.java
+++ b/src/main/java/org/olat/core/commons/services/vfs/ui/version/VFSTrashController.java
@@ -209,7 +209,9 @@ public class VFSTrashController extends FormBasicController implements ProgressD
 	private void doDelete(List<VersionsDeletedFileRow> rowsToDelete) {
 		for(VersionsDeletedFileRow row:rowsToDelete) {
 			VFSRevision revision = vfsRepositoryService.getRevision(new VFSRevisionRefImpl(row.getRevisionKey()));
-			doDelete(revision);
+			if(revision != null) {
+				doDelete(revision);
+			}
 		}
 	}
 	
diff --git a/src/main/java/org/olat/course/assessment/manager/AssessmentNotificationsHandler.java b/src/main/java/org/olat/course/assessment/manager/AssessmentNotificationsHandler.java
index 37fe6ce7bf7a203a2d7ee6ebce8024fd44a90132..f45bd9995a8cc2979b69b4c6ec0898a84e36ab12 100644
--- a/src/main/java/org/olat/course/assessment/manager/AssessmentNotificationsHandler.java
+++ b/src/main/java/org/olat/course/assessment/manager/AssessmentNotificationsHandler.java
@@ -351,9 +351,9 @@ public class AssessmentNotificationsHandler implements NotificationsHandler {
 					for (CourseNode test:testNodes) {
 						List<AssessmentEntry> assessments = courseNodeAssessmentDao.loadAssessmentEntryBySubIdent(cgm.getCourseEntry(), test.getIdent());
 						for(AssessmentEntry assessment:assessments) {
-							Date modDate = assessment.getLastModified();
+							Date modDate = getLater(assessment.getLastUserModified(), assessment.getLastCoachModified());
 							Identity assessedIdentity = assessment.getIdentity();
-							if (modDate.after(compareDate) && (hasFullAccess || coachedUsers.contains(assessedIdentity))) {
+							if (modDate != null && modDate.after(compareDate) && (hasFullAccess || coachedUsers.contains(assessedIdentity))) {
 								BigDecimal score = assessment.getScore();
 								if(test instanceof ScormCourseNode) {
 									ScormCourseNode scormTest = (ScormCourseNode)test;
@@ -405,6 +405,13 @@ public class AssessmentNotificationsHandler implements NotificationsHandler {
 		}
 	}
 	
+	private Date getLater(Date date1, Date date2) {
+		if (date1 == null) return date2;
+		if (date2 == null) return date1;
+		
+		return date1.after(date2)? date1: date2;
+	}
+	
 	private void checkPublisher(Publisher p) {
 		try {
 			if(!NotificationsUpgradeHelper.checkCourse(p)) {