diff --git a/src/main/java/ch/ethz/seb/sebserver/gbl/model/EntityKey.java b/src/main/java/ch/ethz/seb/sebserver/gbl/model/EntityKey.java
index ad785589..cc8a5cac 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gbl/model/EntityKey.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gbl/model/EntityKey.java
@@ -18,15 +18,8 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 
 import ch.ethz.seb.sebserver.gbl.api.EntityType;
 
-/** A EntityKey uniquely identifies a domain entity within the SEB Server's domain model.
- * A EntityKey consists of the model identifier of a domain entity and the type of the entity.
- * JSON:
- * <pre>
- *
- *
- * </pre>
- *
- * */
+/** An EntityKey uniquely identifies a domain entity within the SEB Server's domain model.
+ * An EntityKey consists of the model identifier of a domain entity and the type of the entity. */
 @JsonIgnoreProperties(ignoreUnknown = true)
 public class EntityKey implements ModelIdAware, Serializable {
 
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/ExamDAO.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/ExamDAO.java
index deed1392..2e5cbb4e 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/ExamDAO.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/ExamDAO.java
@@ -114,7 +114,7 @@ public interface ExamDAO extends ActivatableEntityDAO<Exam, Exam>, BulkActionSup
      * @return Result refer to the lock-check-result or to an error if happened */
     Result<Boolean> isLocked(Long examId);
 
-    /** Use this to check of the exam with the specified identifier is up to date
+    /** Use this to check if the exam with the specified identifier is up to date
      *
      * @param examId the exam identifier
      * @param updateId the update identifier of the exam
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
index 758ab9b7..66babe9c 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
@@ -199,6 +199,7 @@ public class ExamSessionServiceImpl implements ExamSessionService {
             log.trace("Running exam request for exam {}", examId);
         }
 
+        updateExamCache(examId);
         final Exam exam = this.examSessionCacheService.getRunningExam(examId);
 
         if (this.examSessionCacheService.isRunning(exam)) {
@@ -327,6 +328,10 @@ public class ExamSessionServiceImpl implements ExamSessionService {
     @Override
     public Result<Exam> updateExamCache(final Long examId) {
         final Exam exam = this.examSessionCacheService.getRunningExam(examId);
+        if (exam == null) {
+            return Result.ofEmpty();
+        }
+
         final Boolean isUpToDate = this.examDAO.upToDate(examId, exam.lastUpdate)
                 .onError(t -> log.error("Failed to verify if cached exam is up to date: {}", exam, t))
                 .getOr(false);
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ConfigurationNodeController.java b/src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ConfigurationNodeController.java
index f79e715b..6a8380a7 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ConfigurationNodeController.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ConfigurationNodeController.java
@@ -270,7 +270,7 @@ public class ConfigurationNodeController extends EntityController<ConfigurationN
         final Result<Configuration> doImport = doImport(password, request, followup);
         if (doImport.hasError()) {
 
-            // rollback if the new configuration
+            // rollback of the new configuration
             this.configurationNodeDAO.delete(new HashSet<>(Arrays.asList(new EntityKey(
                     followup.configurationNodeId,
                     EntityType.CONFIGURATION_NODE))));
@@ -510,6 +510,7 @@ public class ConfigurationNodeController extends EntityController<ConfigurationN
             final String password,
             final HttpServletRequest request,
             final Configuration configuration) throws IOException {
+
         final InputStream inputStream = new BufferedInputStream(request.getInputStream());
         try {