diff --git a/php/public/forms.js b/php/public/forms.js
index 984ae8eb..4202f31e 100644
--- a/php/public/forms.js
+++ b/php/public/forms.js
@@ -12,7 +12,7 @@
     }
     lastError = toast
     body.prepend(toast)
-    setTimeout(toast.remove.bind(toast), 7000)
+    setTimeout(toast.remove.bind(toast), 10000)
   }
 
   function handleEvent(e) {
diff --git a/php/src/Data/ConfigurationManager.php b/php/src/Data/ConfigurationManager.php
index 40990805..9bcf832b 100644
--- a/php/src/Data/ConfigurationManager.php
+++ b/php/src/Data/ConfigurationManager.php
@@ -190,7 +190,7 @@ class ConfigurationManager
     public function SetDomain(string $domain) : void {
         // Validate domain
         if (!filter_var($domain, FILTER_VALIDATE_DOMAIN, FILTER_FLAG_HOSTNAME)) {
-            throw new InvalidSettingConfigurationException("Domain is not in a valid format!");
+            throw new InvalidSettingConfigurationException("Domain is not a valid domain!");
         }
 
         // Validate that it is not an IP-address
@@ -202,14 +202,15 @@ class ConfigurationManager
 
         // Validate IP
         if(!filter_var($dnsRecordIP, FILTER_VALIDATE_IP)) {
-            throw new InvalidSettingConfigurationException("DNS config is not set or domain is not in a valid format!");
+            throw new InvalidSettingConfigurationException("DNS config is not set for this domain or the domain is not a valid domain! (It was found to be set to '" . $dnsRecordIP . "')");
         }
 
-        $connection = @fsockopen($domain, 443, $errno, $errstr, 0.1);
+        // Check if port 443 is open
+        $connection = @fsockopen($domain, 443, $errno, $errstr, 10);
         if ($connection) {
             fclose($connection);
         } else {
-            throw new InvalidSettingConfigurationException("The server is not reachable on Port 443.");
+            throw new InvalidSettingConfigurationException("The server is not reachable on Port 443. You can verify this e.g. with 'https://portchecker.co/' by entering your domain there as ip-address and port 443 as port.");
         }
 
         // Get Instance ID
@@ -223,15 +224,18 @@ class ConfigurationManager
             $protocol = 'http://';
         }
 
+        // Check if response is correct
         $ch = curl_init();
-        curl_setopt($ch, CURLOPT_URL, $protocol . $domain . ':443');
+        $testUrl = $protocol . $domain . ':443';
+        curl_setopt($ch, CURLOPT_URL, $testUrl);
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         $response = (string)curl_exec($ch);
         # Get rid of trailing \n
         $response = str_replace("\n", "", $response);
 
-        if($response !== $instanceID) {
-            throw new InvalidSettingConfigurationException("Domain does not point to this server or reverse proxy not configured correctly.");
+        if ($response !== $instanceID) {
+            error_log('The response of the connection attempt to "' . $testUrl . '" was: ' . $response);
+            throw new InvalidSettingConfigurationException("Domain does not point to this server or the reverse proxy is not configured correctly. See the mastercontainer logs for more details. ('sudo docker logs -f nextcloud-aio-mastercontainer')");
         }
 
         // Write domain