diff --git a/appinfo/info.xml b/appinfo/info.xml
index 414fc8e..477fcb7 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -4,7 +4,7 @@
     <name>Where am I ?</name>
     <summary><![CDATA[Is a simple application to locate everybody in your company.]]></summary>
     <description><![CDATA[Is a simple application to locate everybody in your company.]]></description>
-    <version>0.0.36</version>
+    <version>0.0.37</version>
     <licence>agpl</licence>
     <author mail="contact@adacis.net" homepage="https://www.adacis.net">ADACIS</author>
     <namespace>Whereami</namespace>
@@ -12,7 +12,7 @@
 	<category>organization</category>
     <bugs>https://github.com/Adacis/whereami/issues</bugs>
     <dependencies>
-        <nextcloud min-version="29" max-version="29"/>
+        <nextcloud min-version="29" max-version="31"/>
     </dependencies>
     <settings>
         <admin>OCA\Whereami\Settings\WhereamiAdmin</admin>
diff --git a/lib/MyClass/MyEvent.php b/lib/MyClass/MyEvent.php
index e8c0609..c4a48e3 100755
--- a/lib/MyClass/MyEvent.php
+++ b/lib/MyClass/MyEvent.php
@@ -8,13 +8,13 @@
 
 class MyEvent
 {
-    public String $id;
-    public String $summary;
-    public String $dtStart;
-    public String $dtEnd;
-    public String $place;
-    public String $place2;
-    public String $nextcloud_users;
+    public string $id;
+    public string $summary;
+    public ?string $dtStart;
+    public ?string $dtEnd;
+    public string $place;
+    public string $place2;
+    public string $nextcloud_users;
     public $quote;
 
     public bool $valid;
@@ -31,12 +31,12 @@ public function __construct(
         $this->log = $logger;
         $this->myDb             = $myDb;
         $this->id               = $e['id'];
-        $this->dtStart          = $e["objects"][0]["DTSTART"][0]?->modify('+ 1 minute')?->format('Y-m-d H:i:s');
-        $this->dtEnd            = $e["objects"][0]["DTEND"][0]?->modify('- 1 minute')?->format('Y-m-d H:i:s') ?? $this->dtStart;
+        $this->dtStart          = ($e["objects"][0]["DTSTART"][0] ?? null)?->modify('+ 1 minute')?->format('Y-m-d H:i:s');
+        $this->dtEnd            = ($e["objects"][0]["DTEND"][0] ?? null)?->modify('- 1 minute')?->format('Y-m-d H:i:s') ?? $this->dtStart;
         $this->nextcloud_users  = $this->getNameCalendar($this->id);
-        $this->summary          = str_replace("@", "", $e["objects"][0]["SUMMARY"][0]);
+        $this->summary          = str_replace("@", "", $e["objects"][0]["SUMMARY"][0] ?? '');
 
-        $tmp                    = $this->extractData(",", 0, $e["objects"][0]["SUMMARY"][0]);
+        $tmp                    = $this->extractData(",", 0, $e["objects"][0]["SUMMARY"][0] ?? '');
         if (!is_null($this->dtStart) && count($tmp) > 0) {
             $this->place = $tmp[0];
             if (count($tmp) >= 2) {
@@ -108,9 +108,12 @@ public function extractData($separator, $position, $data): array
         preg_match_all($re, strtolower($data), $matches, PREG_SET_ORDER, 0);
 
         try {
-            $cls = [$matches[0][1]];
-            if (count($matches[0]) >= 4) {
-                array_push($cls, $matches[0][3]);
+            $cls = [];
+            if (isset($matches[0][1])) {
+                $cls[] = $matches[0][1];
+            }
+            if (count($matches[0] ?? []) >= 4) {
+                $cls[] = $matches[0][3];
             }
         } catch (\Throwable $th) {
             $cls = [];
diff --git a/templates/navigation/index.php b/templates/navigation/index.php
index 27ac4cf..474317d 100644
--- a/templates/navigation/index.php
+++ b/templates/navigation/index.php
@@ -1,5 +1,5 @@
 <ul class="app-navigation">
-    <li class="app-navigation-entry"><span class="app-title"></span><b>Where am I V 0.0.36</b></li>
+    <li class="app-navigation-entry"><span class="app-title"></span><b>Where am I V 0.0.37</b></li>
     <li class="app-navigation-entry-link">
         <ul class="app-navigation">
             <li class="active app-navigation-entry-link button new btn-new-event"><span class="navmarg icon-add"></span><a