diff --git a/app/Http/Middleware/Authenticate.php b/app/Http/Middleware/Authenticate.php
index e19afd0cc671..6bb6f4dc7765 100644
--- a/app/Http/Middleware/Authenticate.php
+++ b/app/Http/Middleware/Authenticate.php
@@ -58,8 +58,7 @@ class Authenticate
 
             if ($contact_key) {
                 $contact = $this->getContact($contact_key);
-            } elseif (! empty($request->invitation_key)) {
-                $invitation = $this->getInvitation($request->invitation_key);
+            } elseif ($invitation = $this->getInvitation($request->invitation_key)) {
                 $contact = $invitation->contact;
                 Session::put('contact_key', $contact->contact_key);
             } else {
@@ -104,6 +103,10 @@ class Authenticate
      */
     protected function getInvitation($key)
     {
+        if (! $key) {
+            return false;
+        }
+
         // check for extra params at end of value (from website feature)
         list($key) = explode('&', $key);
 
diff --git a/resources/views/error.blade.php b/resources/views/error.blade.php
index 1ae3d0cb0d66..073720abf895 100644
--- a/resources/views/error.blade.php
+++ b/resources/views/error.blade.php
@@ -9,7 +9,7 @@
   <div class="container" style="min-height:400px">
   <h3>{{ trans('texts.error_title') }}...</h3>
   <h4>{{ $error }}</h4>
-  <h4>{{ trans('texts.error_contact_text', ['mailaddress' => env('MAIL_USERNAME')]) }}</h4>
+  <h4>{{ trans('texts.error_contact_text', ['mailaddress' => env('CONTACT_EMAIL', env('MAIL_USERNAME'))]) }}</h4>
 </div>
 </div>