diff --git a/shogun-boot/src/main/java/de/terrestris/shogun/boot/controller/AuthController.java b/shogun-boot/src/main/java/de/terrestris/shogun/boot/controller/AuthController.java
index f7523afe0..6c56cd7a2 100644
--- a/shogun-boot/src/main/java/de/terrestris/shogun/boot/controller/AuthController.java
+++ b/shogun-boot/src/main/java/de/terrestris/shogun/boot/controller/AuthController.java
@@ -32,7 +32,7 @@
 public class AuthController {
 
     @GetMapping("/isSessionValid")
-    public ResponseEntity<?> isSessionValid(Authentication authentication) {
+    public ResponseEntity<String> isSessionValid(Authentication authentication) {
         log.debug("Checking if user is logged in.");
 
         if (authentication != null && authentication.isAuthenticated()) {
diff --git a/shogun-boot/src/main/resources/templates/error/404.html b/shogun-boot/src/main/resources/templates/error/404.html
index 1f594b77b..949500627 100644
--- a/shogun-boot/src/main/resources/templates/error/404.html
+++ b/shogun-boot/src/main/resources/templates/error/404.html
@@ -56,7 +56,6 @@
           border-radius: 8px;
           -moz-border-radius: 8px;
           margin: auto 70px auto 70px;
-          #padding: 50px;
           top: 50%;
           position: absolute;
           transform: translate(0, -50%);
@@ -86,6 +85,7 @@
             margin-left: auto;
         }
     </style>
+    <title>SHOGun - Error</title>
 </head>
 <body>
 <div id="error">
@@ -94,14 +94,14 @@
             <h1>Oops!</h1>
         </div>
         <div class="error-code">
-            <p th:text="${status}"/>
+            <p th:text="${status}"></p>
         </div>
         <div class="error-text">
           The page you're looking for is not available.
         </div>
         <div class="error-img">
             <!--<img th:src="@{404.gif}"/>-->
-            <img src="https://media.tenor.com/images/2e7080b4048c2975ab525027a5af85f2/tenor.gif">
+            <img src="https://media.tenor.com/images/2e7080b4048c2975ab525027a5af85f2/tenor.gif" alt="Error">
         </div>
     </div>
 
diff --git a/shogun-boot/src/main/resources/templates/index.html b/shogun-boot/src/main/resources/templates/index.html
index 1dcfb518d..d05de9ea0 100644
--- a/shogun-boot/src/main/resources/templates/index.html
+++ b/shogun-boot/src/main/resources/templates/index.html
@@ -42,7 +42,7 @@
   <header
     class="container d-flex flex-wrap align-items-center justify-content-center justify-content-md-between py-3 mb-4 border-bottom">
     <a href="/" class="d-flex align-items-center col-md-3 mb-2 mb-md-0 text-dark text-decoration-none">
-      <img class="header-image" src="./assets/img/shogun_logo.png">
+      <img class="header-image" src="./assets/img/shogun_logo.png" alt="SHOGun logo">
     </a>
     <ul class="nav col-md-3">
       <li class="nav-item">
@@ -103,7 +103,7 @@ <h2 class="pb-2">Welcome to SHOGun</h2>
       <div style="display: none" id="keycloak-host" th:text="${@environment.getProperty('KEYCLOAK_HOST')}"></div>
       <a href="/admin">
         <button id="admin-panel-btn" class="btn btn-primary">
-          Open Admin Panel <i class="fas fa-lock"></i>
+          Open Admin Panel <em class="fas fa-lock"></em>
         </button>
       </a>
       <h3 class="pb-2 pt-4">Applications</h3>
@@ -117,15 +117,15 @@ <h3 class="pb-2 pt-4">Applications</h3>
       &copy; 2021 - present <a href="https://www.terrestris.de">terrestris GmbH & Co. KG</a>
     </p>
     <p class="col-md-3 mb-0 text-muted">
-      <i class="fas fa-plug"></i>
+      <em class="fas fa-plug"></em>
       <a href="./swagger-ui/index.html">Swagger / OpenAPI</a>
     </p>
     <p class="col-md-3 mb-0 text-muted">
-      <i class="fas fa-project-diagram"></i>
+      <em class="fas fa-project-diagram"></em>
       <a href="./graphiql">GraphiQL</a>
     </p>
     <p class="col-md-3 mb-0 text-muted">
-      <i class="fab fa-github"></i>
+      <em class="fab fa-github"></em>
       <a href="https://github.com/terrestris/shogun">GitHub</a>
     </p>
   </footer>
@@ -191,7 +191,7 @@ <h3 class="pb-2 pt-4">Applications</h3>
         appInfos.forEach(app => {
           const html = `<shogun-app app='${app.id}'>` +
             `<a style='visibility: hidden' class='admin-btn' title='Edit application' slot='admin-btn' href='/admin/portal/application/${app.id}'>` +
-            `<i class='fas fa-cog'></i></a>` +
+            `<em class='fas fa-cog'></em></a>` +
             `<span slot='app-title'>${app.name}</span>` +
             `<span slot='app-info'>${app.description}</span>` +
             `</shogun-app>`;
diff --git a/shogun-gs-interceptor/src/main/java/de/terrestris/shogun/interceptor/controller/GeoServerInterceptorController.java b/shogun-gs-interceptor/src/main/java/de/terrestris/shogun/interceptor/controller/GeoServerInterceptorController.java
index 8b3e8a07c..f813323b1 100644
--- a/shogun-gs-interceptor/src/main/java/de/terrestris/shogun/interceptor/controller/GeoServerInterceptorController.java
+++ b/shogun-gs-interceptor/src/main/java/de/terrestris/shogun/interceptor/controller/GeoServerInterceptorController.java
@@ -45,7 +45,7 @@ public class GeoServerInterceptorController {
     protected GeoServerInterceptorService service;
 
     @RequestMapping(value = {"/geoserver.action", "/geoserver.action/{endpoint}"}, method = {RequestMethod.GET, RequestMethod.POST})
-    public ResponseEntity<?> interceptGeoServerRequest(HttpServletRequest request, Optional<String> endpoint) {
+    public ResponseEntity<byte[]> interceptGeoServerRequest(HttpServletRequest request, Optional<String> endpoint) {
         HttpHeaders responseHeaders = new HttpHeaders();
         HttpStatus responseStatus;
         byte[] responseBody;
diff --git a/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/HttpUtil.java b/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/HttpUtil.java
index f047d58e6..3d958ba49 100644
--- a/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/HttpUtil.java
+++ b/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/HttpUtil.java
@@ -20,6 +20,7 @@
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.Part;
+import lombok.Getter;
 import lombok.extern.log4j.Log4j2;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
@@ -65,6 +66,7 @@ public class HttpUtil {
     /**
      * The timeout for all outgoing HTTP connections.
      */
+    @Getter
     private static int httpTimeout;
     /**
      * The default timeout given by the config beans.
@@ -76,14 +78,14 @@ public class HttpUtil {
     private static String AUTHORIZATION_HEADER = "authorization";
 
     /**
-     * Returns the full webapplication URI from a given request.
+     * Returns the full web application URI from a given request.
      * <p>
      * Example:
      * <p>
      * The following GET-request:
-     * http://localhost:8080/shogun/user/resetPassword.action
+     * <a href="http://localhost:8080/shogun/user/resetPassword.action">...</a>
      * will result in
-     * http://localhost:8080/shogun/
+     * <a href="http://localhost:8080/shogun/">...</a>
      *
      * @param request
      * @return
@@ -2185,13 +2187,6 @@ private static HttpHost getSystemProxy(URI uri) throws UnknownHostException {
         return systemProxy;
     }
 
-    /**
-     * @return the httpTimeout
-     */
-    public static int getHttpTimeout() {
-        return httpTimeout;
-    }
-
     /**
      * @param httpTimeout the httpTimeout to set
      */
diff --git a/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/KeycloakUtil.java b/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/KeycloakUtil.java
index 84485b00f..b49abb77d 100644
--- a/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/KeycloakUtil.java
+++ b/shogun-lib/src/main/java/de/terrestris/shogun/lib/util/KeycloakUtil.java
@@ -125,7 +125,7 @@ public GroupRepresentation addGroup(String groupName) throws WebApplicationExcep
         if (!availableGroups.isEmpty()) {
             log.debug("Group {} already exists.", groupName);
 
-            return availableGroups.get(0);
+            return availableGroups.getFirst();
         }
 
         GroupRepresentation group = new GroupRepresentation();
