diff --git a/VERSION.txt b/VERSION.txt
index fe4e95430601..0fe15a58a412 100644
--- a/VERSION.txt
+++ b/VERSION.txt
@@ -1 +1 @@
-5.8.20
\ No newline at end of file
+5.8.21
\ No newline at end of file
diff --git a/app/Console/Commands/CheckData.php b/app/Console/Commands/CheckData.php
index 709ccecc0d59..79c98f656c7f 100644
--- a/app/Console/Commands/CheckData.php
+++ b/app/Console/Commands/CheckData.php
@@ -934,6 +934,21 @@ class CheckData extends Command
             });
 
 
+            Invoice::withTrashed()
+            ->where("partial", 0)
+            ->whereNotNull("partial_due_date")
+            ->cursor()
+            ->each(function ($i) {
+                $i->partial_due_date = null;
+                $i->saveQuietly();
+
+                
+                $this->logMessage("Fixing partial due date for # {$i->id}");
+
+            });
+
+
+
 
         }
     }
diff --git a/app/Http/ValidationRules/Ninja/CanAddUserRule.php b/app/Http/ValidationRules/Ninja/CanAddUserRule.php
index 6e19dbd09b14..1e4a51b7b7f2 100644
--- a/app/Http/ValidationRules/Ninja/CanAddUserRule.php
+++ b/app/Http/ValidationRules/Ninja/CanAddUserRule.php
@@ -31,21 +31,37 @@ class CanAddUserRule implements Rule
      */
     public function passes($attribute, $value)
     {
+        /** @var \App\Models\User $user */
+        $user = auth()->user();
+
         /* If the user is active then we can add them to the company */
-        if (User::where('email', request()->input('email'))->where('account_id', auth()->user()->account_id)->where('is_deleted', 0)->exists()) {
+        if (User::where('email', request()->input('email'))->where('account_id', $user->account_id)->where('is_deleted', 0)->exists()) {
             return true;
         }
 
-        /* Check that we have sufficient quota to allow this to happen */
+        /* 
+        Check that we have sufficient quota to allow this to happen 
+
+        @ 31-01-2024 - changed query to use email instead of user_id
+        
         $count = CompanyUser::query()
-                          ->where('company_user.account_id', auth()->user()->account_id)
+                          ->where('company_user.account_id', $user->account_id)
                           ->join('users', 'users.id', '=', 'company_user.user_id')
                           ->whereNull('users.deleted_at')
                           ->whereNull('company_user.deleted_at')
                           ->distinct()
                           ->count('company_user.user_id');
+        */
 
-        return $count < auth()->user()->company()->account->num_users;
+        $count = CompanyUser::query()
+                        ->where("company_user.account_id", $user->account_id)
+                        ->join("users", "users.id", "=", "company_user.user_id")
+                        ->whereNull("users.deleted_at")
+                        ->whereNull("company_user.deleted_at")
+                        ->distinct()
+                        ->count("users.email");
+
+        return $count < $user->company()->account->num_users;
     }
 
     /**
@@ -53,6 +69,11 @@ class CanAddUserRule implements Rule
      */
     public function message()
     {
-        return ctrans('texts.limit_users', ['limit' => auth()->user()->company()->account->num_users]);
+        
+        /** @var \App\Models\User $user */
+        $user = auth()->user();
+
+        return ctrans('texts.limit_users', ['limit' => $user->company()->account->num_users]);
+
     }
 }
diff --git a/config/ninja.php b/config/ninja.php
index bb996122096e..a88e422fcaf3 100644
--- a/config/ninja.php
+++ b/config/ninja.php
@@ -17,8 +17,8 @@ return [
     'require_https' => env('REQUIRE_HTTPS', true),
     'app_url' => rtrim(env('APP_URL', ''), '/'),
     'app_domain' => env('APP_DOMAIN', 'invoicing.co'),
-    'app_version' => env('APP_VERSION', '5.8.20'),
-    'app_tag' => env('APP_TAG', '5.8.20'),
+    'app_version' => env('APP_VERSION', '5.8.21'),
+    'app_tag' => env('APP_TAG', '5.8.21'),
     'minimum_client_version' => '5.0.16',
     'terms_version' => '1.0.1',
     'api_secret' => env('API_SECRET', false),
diff --git a/resources/views/email/template/plain.blade.php b/resources/views/email/template/plain.blade.php
index 3d87e093eb6e..c66249b20235 100644
--- a/resources/views/email/template/plain.blade.php
+++ b/resources/views/email/template/plain.blade.php
@@ -46,5 +46,5 @@
 @endisset
 
 @isset($email_preferences)
-<p><a href="{{$unsubscribe_link}}">{{ ctrans('texts.unsubscribe') }}</a></p>
+<p><a href="{!! $email_preferences !!}">{{ ctrans('texts.unsubscribe') }}</a></p>
 @endisset
\ No newline at end of file