diff --git a/src/main/java/org/olat/core/gui/components/table/BooleanColumnDescriptor.java b/src/main/java/org/olat/core/gui/components/table/BooleanColumnDescriptor.java
index 3d05fd65610970292b305fd5533aadc2f7126ff2..79ae772fcb1b7baf2f11b237951f87cdb838812f 100644
--- a/src/main/java/org/olat/core/gui/components/table/BooleanColumnDescriptor.java
+++ b/src/main/java/org/olat/core/gui/components/table/BooleanColumnDescriptor.java
@@ -76,28 +76,29 @@ public class BooleanColumnDescriptor extends DefaultColumnDescriptor {
 	 * @see org.olat.core.gui.components.table.ColumnDescriptor#renderValue(org.olat.core.gui.render.StringOutput,
 	 *      int, org.olat.core.gui.render.Renderer)
 	 */
+	@Override
 	public void renderValue(final StringOutput sb, final int row, final Renderer renderer) {
-		Boolean bool = (Boolean) getModelData(row);
-		boolean appendNothing = bool == null;
-		if (appendNothing){
-			return;
-		}
-		String val = (bool.booleanValue() ? trueValue : falseValue);
-		if(StringHelper.containsNonWhitespace(val)) {
-			sb.append(val);
+		Object obj = getModelData(row);
+		if(obj instanceof Boolean) {
+			Boolean bool = (Boolean)obj;
+			String val = (bool.booleanValue() ? trueValue : falseValue);
+			if(StringHelper.containsNonWhitespace(val)) {
+				sb.append(val);
+			}
 		}
 	}
 
 	/**
 	 * @see org.olat.core.gui.components.table.ColumnDescriptor#getAction(int)
 	 */
+	@Override
 	public String getAction(final int row) {
 		if (!hasAction) {
 			return null;
 		} else {
-			Boolean bool = (Boolean) getModelData(row);
+			Object bool = getModelData(row);
 			// make sure the bool is not null before checkings its value
-			if (bool != null && bool.booleanValue()) {
+			if (bool instanceof Boolean && ((Boolean)bool).booleanValue()) {
 				return super.getAction(row);
 			} else {
 				return null;
diff --git a/src/main/java/org/olat/group/manager/BusinessGroupMailing.java b/src/main/java/org/olat/group/manager/BusinessGroupMailing.java
index 583295d29047ede9f8b0ed163c6d2ec01cb65e4e..111d77dabe32888c0d9e143d8d5556b5eb8c6443 100644
--- a/src/main/java/org/olat/group/manager/BusinessGroupMailing.java
+++ b/src/main/java/org/olat/group/manager/BusinessGroupMailing.java
@@ -113,8 +113,9 @@ public class BusinessGroupMailing {
 		if(context == null) {
 			context = new MailContextImpl(null, null, "[BusinessGroup:" + group.getKey() + "]");
 		}
-
-		MailerResult result = mailer.sendMailAsSeparateMails(context, Collections.singletonList(identity), null, template, ureqIdentity, mailing.getUuid());
+		
+		String metaId = mailing != null ? mailing.getUuid() : null;
+		MailerResult result = mailer.sendMailAsSeparateMails(context, Collections.singletonList(identity), null, template, ureqIdentity, metaId);
 		if(mailing != null) {
 			mailing.appendResult(result);
 		}
diff --git a/src/main/java/org/olat/repository/RepositoryMailing.java b/src/main/java/org/olat/repository/RepositoryMailing.java
index ce55f09ed5e65d5301df63550330aea6448ee0d4..1a5f6894899ea07536bb2087b43d69e8bce60a7d 100644
--- a/src/main/java/org/olat/repository/RepositoryMailing.java
+++ b/src/main/java/org/olat/repository/RepositoryMailing.java
@@ -126,7 +126,8 @@ public class RepositoryMailing {
 			context = new MailContextImpl(null, null, "[RepositoryEntry:" + re.getKey() + "]");
 		}
 
-		MailerResult result = mailer.sendMailAsSeparateMails(context, Collections.singletonList(identity), null, template, ureqIdentity, mailing.getUuid());
+		String metaId = mailing == null ? null : mailing.getUuid();
+		MailerResult result = mailer.sendMailAsSeparateMails(context, Collections.singletonList(identity), null, template, ureqIdentity, metaId);
 		if(mailing != null) {
 			mailing.appendResult(result);
 		}