diff --git a/src/main/java/ch/ethz/seb/sebserver/gbl/util/Result.java b/src/main/java/ch/ethz/seb/sebserver/gbl/util/Result.java
index be328b3f..5eba6fe6 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gbl/util/Result.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gbl/util/Result.java
@@ -324,7 +324,7 @@ public final class Result<T> {
         }
     }
 
-    public static Result<Void> tryCatch(final Runnable runnable) {
+    public static Result<Void> tryCatch(final TryCatchRunnable runnable) {
         try {
             runnable.run();
             return Result.EMPTY;
@@ -389,4 +389,8 @@ public final class Result<T> {
         T get() throws Exception;
     }
 
+    public interface TryCatchRunnable {
+        void run() throws Exception;
+    }
+
 }
diff --git a/src/main/java/ch/ethz/seb/sebserver/gbl/util/Utils.java b/src/main/java/ch/ethz/seb/sebserver/gbl/util/Utils.java
index 05b4e64c..488bc9d9 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gbl/util/Utils.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gbl/util/Utils.java
@@ -587,35 +587,6 @@ public final class Utils {
         return (hexString.length() < 2) ? "0" + hexString : hexString;
     }
 
-    public static String toJsonObject(final Map<String, String> attributes) {
-        if (attributes == null || attributes.isEmpty()) {
-            return StringUtils.EMPTY;
-        }
-
-        final StringBuilder builder = attributes
-                .entrySet()
-                .stream()
-                .reduce(
-                        new StringBuilder(Constants.CURLY_BRACE_OPEN),
-                        (sb, entry) -> sb
-                                .append(Constants.DOUBLE_QUOTE)
-                                .append(entry.getKey())
-                                .append(Constants.DOUBLE_QUOTE)
-                                .append(Constants.COLON)
-                                .append(getJSONValue(entry.getValue()))
-                                .append(Constants.COMMA),
-                        StringBuilder::append)
-                .append(Constants.CURLY_BRACE_CLOSE);
-
-        if (builder.length() > 0) {
-            return builder
-                    .deleteCharAt(builder.length() - 1)
-                    .toString();
-        } else {
-            return StringUtils.EMPTY;
-        }
-    }
-
     private static String getJSONValue(final String value) {
         if (Constants.TRUE_STRING.equalsIgnoreCase(value) || Constants.FALSE_STRING.equalsIgnoreCase(value)) {
             return value.toLowerCase();
diff --git a/src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringClientConnection.java b/src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringClientConnection.java
index d98f5f3d..36fec927 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringClientConnection.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringClientConnection.java
@@ -262,7 +262,6 @@ public class MonitoringClientConnection implements TemplateComposer {
 
                             NOTIFICATION_LIST_NO_SELECTION_KEY)
                     .noEventPropagation()
-
                     .publishIf(() -> currentUser.get().hasRole(UserRole.EXAM_SUPPORTER), false);
 
             _notificationTableSupplier = () -> notificationTable;
@@ -396,15 +395,6 @@ public class MonitoringClientConnection implements TemplateComposer {
                             .publish();
                 }
 
-//                actionBuilder
-//                        .newAction(ActionDefinition.MONITOR_EXAM_CLIENT_CONNECTION_EXAM_ROOM_PROCTORING)
-//                        .withEntityKey(parentEntityKey)
-//                        .withExec(action -> this.monitoringProctoringService.openExamCollectionProctorScreen(
-//                                action,
-//                                connectionData))
-//                        .noEventPropagation()
-//                        .publish();
-
                 clientConnectionDetails.setStatusChangeListener(ccd -> {
                     this.pageService.firePageEvent(
                             new ActionActivationEvent(
@@ -426,6 +416,11 @@ public class MonitoringClientConnection implements TemplateComposer {
         final EntityKey entityKey = table.getSingleSelection();
         final EntityKey parentEntityKey = pageAction.getParentEntityKey();
 
+        if (entityKey == null) {
+            pageAction.pageContext().publishInfo(NOTIFICATION_LIST_NO_SELECTION_KEY);
+            return pageAction;
+        }
+
         this.pageService.getRestService()
                 .getBuilder(ConfirmPendingClientNotification.class)
                 .withURIVariable(API.PARAM_PARENT_MODEL_ID, parentEntityKey.modelId)
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientInstructionServiceImpl.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientInstructionServiceImpl.java
index 988490d1..ef061cf4 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientInstructionServiceImpl.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientInstructionServiceImpl.java
@@ -34,7 +34,6 @@ import ch.ethz.seb.sebserver.gbl.model.session.ClientInstruction.InstructionType
 import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
 import ch.ethz.seb.sebserver.gbl.util.Result;
 import ch.ethz.seb.sebserver.gbl.util.SizedArrayNonBlockingQueue;
-import ch.ethz.seb.sebserver.gbl.util.Utils;
 import ch.ethz.seb.sebserver.webservice.WebserviceInfo;
 import ch.ethz.seb.sebserver.webservice.datalayer.batis.model.ClientInstructionRecord;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.ClientConnectionDAO;
@@ -143,7 +142,7 @@ public class SEBClientInstructionServiceImpl implements SEBClientInstructionServ
 
         return Result.tryCatch(() -> {
 
-            final String attributesString = Utils.toJsonObject(attributes);
+            final String attributesString = this.jsonMapper.writeValueAsString(attributes);
             final Set<String> activeConnections = this.clientConnectionDAO
                     .filterForInstructionStatus(examId, connectionTokens)
                     .getOrElse(Collections::emptySet);