diff --git a/src/main/java/org/codelibs/fess/helper/ViewHelper.java b/src/main/java/org/codelibs/fess/helper/ViewHelper.java
index 87b19729e..cbc451c6c 100644
--- a/src/main/java/org/codelibs/fess/helper/ViewHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/ViewHelper.java
@@ -147,9 +147,13 @@ public class ViewHelper {
         highlightTagPost = fessConfig.getQueryHighlightTagPost();
         highlightedFields = fessConfig.getQueryHighlightContentDescriptionFieldsAsArray();
         fessConfig.getQueryHighlightTerminalChars().codePoints().forEach(hihglightTerminalCharSet::add);
-        final ServletContext servletContext = ComponentUtil.getComponent(ServletContext.class);
-        servletContext.setSessionTrackingModes(fessConfig.getSessionTrackingModesAsSet().stream().map(s -> SessionTrackingMode.valueOf(s))
-                .collect(Collectors.toSet()));
+        try {
+            final ServletContext servletContext = ComponentUtil.getComponent(ServletContext.class);
+            servletContext.setSessionTrackingModes(fessConfig.getSessionTrackingModesAsSet().stream().map(SessionTrackingMode::valueOf)
+                    .collect(Collectors.toSet()));
+        } catch (final Throwable t) {
+            logger.warn("Failed to set SessionTrackingMode.", t);
+        }
     }
 
     public String getContentTitle(final Map<String, Object> document) {
diff --git a/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java b/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
index eef4f6ee1..01404f026 100644
--- a/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
+++ b/src/main/java/org/codelibs/fess/mylasta/direction/FessProp.java
@@ -1995,8 +1995,8 @@ public interface FessProp {
     String getSessionTrackingModes();
 
     default Set<String> getSessionTrackingModesAsSet() {
-        return split(getSessionTrackingModes(), ",")
-                .get(stream -> stream.map(s -> s.trim().toUpperCase(Locale.ENGLISH)).collect(Collectors.toSet()));
+        return split(getSessionTrackingModes(), ",").get(
+                stream -> stream.map(s -> s.trim().toUpperCase(Locale.ENGLISH)).collect(Collectors.toSet()));
     }
 
 }