diff --git a/wp-plugin/srf-weather-widget/SrfWeatherWidgetApiClient.php b/wp-plugin/srf-weather-widget/SrfWeatherWidgetApiClient.php
index 48b6d3f..e1c85c8 100644
--- a/wp-plugin/srf-weather-widget/SrfWeatherWidgetApiClient.php
+++ b/wp-plugin/srf-weather-widget/SrfWeatherWidgetApiClient.php
@@ -22,7 +22,7 @@ public static function getAccessToken($key, $secret)
         );
         $body = json_decode(wp_remote_retrieve_body($response), true);
 
-        return $body['access_token'];
+        return isset($body['access_token']) ? $body['access_token'] : '';
     }
 
     public static function getGeolocationNames($geolocationName, $accessToken) {
diff --git a/wp-plugin/srf-weather-widget/SrfWeatherWidgetSettings.php b/wp-plugin/srf-weather-widget/SrfWeatherWidgetSettings.php
index b39009e..58ef003 100644
--- a/wp-plugin/srf-weather-widget/SrfWeatherWidgetSettings.php
+++ b/wp-plugin/srf-weather-widget/SrfWeatherWidgetSettings.php
@@ -7,7 +7,7 @@ class SrfWeatherWidgetSettings {
     const DEFAULT_LOCATION = 'srf-weather-api-geolocation';
     const DEFAULT_LOCATION_NAME = 'srf-weather-api-geolocation-name';
 
-
+    static $credentials = [];
 
     public function __construct()
     {
@@ -17,7 +17,7 @@ public function __construct()
 
     public static function validateGeolocation($value) {
         if (!$value) {
-            return $value;
+            return '';
         }
 
         if (!strpos($value, ',')) {
@@ -30,11 +30,16 @@ public static function validateGeolocation($value) {
             return $value;
         }
 
-        // Use the given keys to fetch the nearest point. Use the submittet options, not the
-        // stored one for that.
+        // Use the given keys to fetch the nearest point. Use the submitted options, not the
+        // stored one for that (because a user can change them and it should work initially).
         $key = $_POST[SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY];
         $secret = $_POST[SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET];
+
         $token = SrfWeatherWidgetApiClient::getAccessToken($key, $secret);
+        if (!$token) {
+
+            return $value;
+        }
         $parts = array_filter(explode(',', $value), 'trim');
         $nearest = SrfWeatherWidgetApiClient::getNearestGeolocations($parts[0], $parts[1], $token);
         if (!count($nearest)) {
@@ -46,12 +51,13 @@ public static function validateGeolocation($value) {
 
             return $value;
         } else {
-
+            // update the geolocation name as well
+            $_POST[SrfWeatherWidgetSettings::DEFAULT_LOCATION_NAME] = $nearest[0]['default_name']; // keep it simple
             return $nearest[0]['id'];
         }
     }
 
-    public static function validateNotEmptyApiKey($value) {
+    public static function validateNonEmptyKey($value) {
         if (!$value) {
             add_settings_error(
                 SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY,
@@ -60,23 +66,44 @@ public static function validateNotEmptyApiKey($value) {
             );
 
             return get_option(SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY);
+;
         }
+        self::$credentials['key'] = $value;
 
         return $value;
     }
 
-    public static function validateNotEmptyApiSecret($value) {
+    public static function validateConnection($value) {
+        // not blank
         if (!$value) {
             add_settings_error(
                 SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET,
                 'not empty',
                 'App Secret must not be empty.'
             );
+            return get_option(SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET);
+;
+        }
+        // no api key stored for some reason
+        if (!isset(self::$credentials['key'])) {
+
+            return get_option(SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET);
+; // dont validate further
+        }
+        // validate connection (by retrieving an access token
+        $accessToken = SrfWeatherWidgetApiClient::getAccessToken(self::$credentials['key'], $value);
+        if (!$accessToken) {
+            add_settings_error(
+                SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET,
+                'no connection',
+                'Either API Key or API Secret is wrong.'
+            );
 
             return get_option(SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET);
+            ;
         }
 
-        return $value;
+        return self::$credentials['secret'] = $value;
     }
 
 
@@ -96,8 +123,8 @@ public static function displayWeatherWidgetSettings() {
     }
 
     public static function initSettings() {
-        register_setting(self::SRF_WEATHER_OPTION_GROUP, self::SRF_WEATHER_API_KEY, [SrfWeatherWidgetSettings::class]);
-        register_setting(self::SRF_WEATHER_OPTION_GROUP, self::SRF_WEATHER_API_SECRET, [SrfWeatherWidgetSettings::class]);
+        register_setting(self::SRF_WEATHER_OPTION_GROUP, self::SRF_WEATHER_API_KEY, [SrfWeatherWidgetSettings::class, 'validateNonEmptyKey']);
+        register_setting(self::SRF_WEATHER_OPTION_GROUP, self::SRF_WEATHER_API_SECRET, [SrfWeatherWidgetSettings::class, 'validateConnection']);
         register_setting(self::SRF_WEATHER_OPTION_GROUP, self::DEFAULT_LOCATION, [SrfWeatherWidgetSettings::class, 'validateGeolocation']);
         register_setting(self::SRF_WEATHER_OPTION_GROUP, self::DEFAULT_LOCATION_NAME);
     }
diff --git a/wp-plugin/srf-weather-widget/tpl/admin_settings.tpl.php b/wp-plugin/srf-weather-widget/tpl/admin_settings.tpl.php
index 5e6bc6a..e03a01c 100644
--- a/wp-plugin/srf-weather-widget/tpl/admin_settings.tpl.php
+++ b/wp-plugin/srf-weather-widget/tpl/admin_settings.tpl.php
@@ -32,21 +32,21 @@
                 <p>To get an SRF Meteo API Key <a href="https://developer.srgssr.ch/user/register">register here</a> and add the Meteo App <a href="https://developer.srgssr.ch/user/4205/create-app">here</a>. Use the "SRF-MeteoProductFreemium" Product to get a free account.
                 </p>
                 <p class="alert-info">Note: The Meteo API only returns data for places in Switzerland.</p>
-                <label for="srf-weather-widget-auth-key">App ID:</label>
-                <input type="text" id="srf-weather-widget-auth-key" name="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY; ?>" value="<?php echo esc_attr($apiKey); ?>" />
+                <label for="srf-weather-widget-auth-key">App ID*</label>
+                <input type="text" required="true" id="srf-weather-widget-auth-key" name="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY; ?>" value="<?php echo esc_attr($apiKey); ?>" />
                 <span class="error-field"><?= ($errorFields[SrfWeatherWidgetSettings::SRF_WEATHER_API_KEY] ?? ''); ?></span>
 
-                <label for="srf-weather-widget-auth-secret">App Secret:</label>
-                <input type="text" id="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET; ?>" name="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET; ?>" value="<?php echo esc_attr($apiSecret); ?>" />
+                <label for="srf-weather-widget-auth-secret">App Secret*</label>
+                <input type="text" required="true" id="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET; ?>" name="<?=SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET; ?>" value="<?php echo esc_attr($apiSecret); ?>" />
                 <span class="error-field"><?= ($errorFields[SrfWeatherWidgetSettings::SRF_WEATHER_API_SECRET] ?? ''); ?></span>
 
 
                 <h3>Default location</h3>
                 <p>Set either a default location by its location-id (most accurate results, but the api must be used to find out a correct location). Or just use the name of the city.</p>
-                <label for="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION; ?>">Default location-id (lat,lon):</label>
+                <label for="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION; ?>">Default location-id (lat,lon). Will be rounded to the nearest point with forecasts available.</label>
                 <input type="text" id="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION; ?>" name="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION; ?>" value="<?php echo esc_attr($location); ?>" />
                 <span class="error-field"><?= ($errorFields[SrfWeatherWidgetSettings::DEFAULT_LOCATION] ?? ''); ?></span>
-                <label for=<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION_NAME; ?>>Default location name (if no location is given, search by name)</label>
+                <label for=<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION_NAME; ?>>Default location name. Only set if you don't know the geolocation and have a unique name (like Zurich or Bern)</label>
                 <input type="text" id="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION_NAME; ?>" name="<?=SrfWeatherWidgetSettings::DEFAULT_LOCATION_NAME;?>" value="<?php echo esc_attr($locationName); ?>" />
                 <?php submit_button(); ?>
             </form>