diff --git a/src/main/java/org/olat/course/config/ui/courselayout/CourseLayoutGeneratorController.java b/src/main/java/org/olat/course/config/ui/courselayout/CourseLayoutGeneratorController.java
index dc3904e02cad4d0bfb5940a05e104d1ddf3cf320..4cdc20f2b5790e87626186f5ad02b33980754ff4 100644
--- a/src/main/java/org/olat/course/config/ui/courselayout/CourseLayoutGeneratorController.java
+++ b/src/main/java/org/olat/course/config/ui/courselayout/CourseLayoutGeneratorController.java
@@ -281,11 +281,13 @@ public class CourseLayoutGeneratorController extends FormBasicController {
 	private boolean processUploadedImage(File image){
 		int height = 0;
 		int width = 0;
-		String size[] = customCMgr.getImageSize(image);
+		int[] size = customCMgr.getImageSize(image);
 		if (size != null) {
-			width = Integer.parseInt(size[0]);
-			height = Integer.parseInt(size[1]);
-		} else return false;
+			width = size[0];
+			height = size[1];
+		} else {
+			return false;
+		}
 		// target file:
 		String fileType = logoUpl.getUploadFileName().substring(logoUpl.getUploadFileName().lastIndexOf("."));
 		VFSContainer base = (VFSContainer) courseEnvironment.getCourseBaseContainer().resolve(CourseLayoutHelper.LAYOUT_COURSE_SUBFOLDER);
diff --git a/src/main/java/org/olat/course/config/ui/courselayout/CustomConfigManager.java b/src/main/java/org/olat/course/config/ui/courselayout/CustomConfigManager.java
index fc44b0896ce03760deeaabe5dc7e18d58edef457..f6a672c35cdb30c313695a21e57e3783176fa45e 100644
--- a/src/main/java/org/olat/course/config/ui/courselayout/CustomConfigManager.java
+++ b/src/main/java/org/olat/course/config/ui/courselayout/CustomConfigManager.java
@@ -119,9 +119,11 @@ public class CustomConfigManager extends BasicManager {
 			sb.append("\tbackground-position: left top; \n");
 			sb.append("\tbackground-repeat: no-repeat; \n");
 			LocalFileImpl leaf = (LocalFileImpl) vfsItem;
-			String size[] = getImageSize(leaf.getBasefile());
-			sb.append("\twidth: ").append(size[0]).append("px; \n");
-			sb.append("\theight: ").append(size[1]).append("px; \n");
+			int[] size = getImageSize(leaf.getBasefile());
+			if(size != null) {
+				sb.append("\twidth: ").append(size[0]).append("px; \n")
+				  .append("\theight: ").append(size[1]).append("px; \n");
+			}
 			sb.append("\tfloat: left; \n}\n");
 			sb.append("#o_logo { \n\t float: left; \n}");
 		}
@@ -142,18 +144,22 @@ public class CustomConfigManager extends BasicManager {
 	 * @param image
 	 * @return array[width, height]
 	 */
-	public String[] getImageSize(File image){
+	public int[] getImageSize(File image){
 		int height = 0;
 		int width = 0;
 		try {
 			BufferedImage imageSrc = ImageIO.read(image);
-			height = imageSrc.getHeight();
-			width = imageSrc.getWidth();
+			if(imageSrc != null) {
+				height = imageSrc.getHeight();
+				width = imageSrc.getWidth();
+			} else {
+				return null;
+			}
 		} catch (IOException e) {
 			logError("Problem reading uploaded image", e);
 			return null;
 		}
-		return new String[] { String.valueOf(width), String.valueOf(height) };
+		return new int[] { width, height };
 	}
 	
 	/**
diff --git a/src/main/java/org/olat/course/nodes/cl/ui/CheckListAssessmentController.java b/src/main/java/org/olat/course/nodes/cl/ui/CheckListAssessmentController.java
index c2f1738bb2e2474901e1d59f808b9f6960c793ee..68776e15ddfc8e4880c4514082e6e1c04d7f3ac2 100644
--- a/src/main/java/org/olat/course/nodes/cl/ui/CheckListAssessmentController.java
+++ b/src/main/java/org/olat/course/nodes/cl/ui/CheckListAssessmentController.java
@@ -291,8 +291,9 @@ public class CheckListAssessmentController extends FormBasicController implement
 		if(courseTutor || courseAdmin) {
 			List<RepositoryEntryMembership> repoMemberships = repositoryManager.getRepositoryEntryMembership(re);
 			for(RepositoryEntryMembership repoMembership:repoMemberships) {
-				if(repoMembership.isParticipant()) continue;
-				missingIdentityKeys.add(repoMembership.getIdentityKey());
+				if(repoMembership.isParticipant()) {
+					missingIdentityKeys.add(repoMembership.getIdentityKey());
+				}
 			}
 		}