diff --git a/admin/service_messages.php b/admin/service_messages.php
index 052e0eb4..a3efb682 100644
--- a/admin/service_messages.php
+++ b/admin/service_messages.php
@@ -127,8 +127,8 @@
             <form id="service-message" class="form-horizontal" data-toggle="validator" method="post">
                 <div class="modal-body">
                     <ul class="nav nav-tabs" role="tablist">
-                        <li role="presentation" class="active"><a href="#sm-contents" role="tab" data-toggle="tab">Contents</a></li>
-                        <li role="presentation"><a href="#properties" role="tab" data-toggle="tab">Properties</a></li>
+                        <li role="presentation" class="active"><a href="#sm-contents" role="tab" data-toggle="tab"><?php echo $hesklang['kb_content']; ?></a></li>
+                        <li role="presentation"><a href="#properties" role="tab" data-toggle="tab"><?php echo $hesklang['properties']; ?></a></li>
                     </ul><br>
                     <div class="tab-content">
                         <div role="tabpanel" class="tab-pane active" id="sm-contents">
diff --git a/api/Controllers/Tickets/StaffTicketController.php b/api/Controllers/Tickets/StaffTicketController.php
index e049bca5..7cefe216 100644
--- a/api/Controllers/Tickets/StaffTicketController.php
+++ b/api/Controllers/Tickets/StaffTicketController.php
@@ -10,6 +10,7 @@
 use BusinessLogic\Tickets\TicketEditor;
 use BusinessLogic\Tickets\TicketRetriever;
 use Controllers\JsonRetriever;
+use Symfony\Component\Console\Helper\Helper;
 
 class StaffTicketController extends \BaseClass {
     function get($id) {
@@ -55,7 +56,14 @@ static function updateDueDate($id) {
 
         $json = JsonRetriever::getJsonData();
 
-        $dueDate = date('Y-m-d H:i:s', strtotime(Helpers::safeArrayGet($json, 'dueDate')));
+        $newDueDate = Helpers::safeArrayGet($json, 'dueDate');
+
+        if ($newDueDate !== null) {
+            $dueDate = date('Y-m-d H:i:s', strtotime(Helpers::safeArrayGet($json, 'dueDate')));
+        } else {
+            $dueDate = null;
+        }
+
 
         $ticketEditor->updateDueDate($id, $dueDate, $userContext, $hesk_settings);
     }
diff --git a/build.php b/build.php
index 189c8f08..a33f04d7 100644
--- a/build.php
+++ b/build.php
@@ -1,4 +1,4 @@
 <?php
 
 // Define the current build
-define('MODS_FOR_HESK_BUILD', 50);
+define('MODS_FOR_HESK_BUILD', 51);
diff --git a/calendar.php b/calendar.php
index 64488e4c..2f788a8c 100644
--- a/calendar.php
+++ b/calendar.php
@@ -120,11 +120,11 @@
     <p id="setting_default_view"><?php echo $modsForHesk_settings['default_calendar_view']; ?></p>
     <p id="setting_first_day_of_week"><?php echo $modsForHesk_settings['first_day_of_week']; ?></p>
     <p id="setting_show_start_time"><?php echo $modsForHesk_settings['calendar_show_start_time']; ?></p>
-</div>
-<?php
-$businessHoursRs = hesk_dbQuery("SELECT * FROM `" . hesk_dbEscape($hesk_settings['db_pfix']) . "mfh_calendar_business_hours`");
-while ($row = hesk_dbFetchAssoc($businessHoursRs)):
-    ?>
-    <p id="business_hours_<?php echo $row['day_of_week']; ?>_start"><?php echo $row['start_time']; ?></p>
-    <p id="business_hours_<?php echo $row['day_of_week']; ?>_end"><?php echo $row['end_time']; ?></p>
-<?php endwhile; ?>
\ No newline at end of file
+    <?php
+    $businessHoursRs = hesk_dbQuery("SELECT * FROM `" . hesk_dbEscape($hesk_settings['db_pfix']) . "mfh_calendar_business_hours`");
+    while ($row = hesk_dbFetchAssoc($businessHoursRs)):
+        ?>
+        <p id="business_hours_<?php echo $row['day_of_week']; ?>_start"><?php echo $row['start_time']; ?></p>
+        <p id="business_hours_<?php echo $row['day_of_week']; ?>_end"><?php echo $row['end_time']; ?></p>
+    <?php endwhile; ?>
+</div>
\ No newline at end of file
diff --git a/inc/headerAdmin.inc.php b/inc/headerAdmin.inc.php
index 37976b7b..8b5af140 100644
--- a/inc/headerAdmin.inc.php
+++ b/inc/headerAdmin.inc.php
@@ -194,7 +194,7 @@
     /* If page requires WYSIWYG editor include TinyMCE Javascript */
     if (defined('WYSIWYG') && $hesk_settings['kb_wysiwyg']) {
         ?>
-        <script type="text/javascript" src="<?php echo HESK_PATH; ?>inc/tiny_mce/3.5.11/tiny_mce.js"></script>
+        <script type="text/javascript" src="<?php echo HESK_PATH; ?>inc/tiny_mce/3.5.12/tiny_mce.js"></script>
         <?php
     }
 
diff --git a/install/migrations/core.php b/install/migrations/core.php
index e02a83ca..3a48ce6c 100644
--- a/install/migrations/core.php
+++ b/install/migrations/core.php
@@ -228,5 +228,6 @@ function getAllMigrations() {
         170 => new \v330\CalendarImprovements\AddShowStartTimeSetting(170),
         171 => new \v330\AddHighlightTicketRowsSetting(171),
         172 => new UpdateMigration('3.3.0', '3.2.5', 172),
+        173 => new UpdateMigration('3.3.1', '3.3.0', 173),
     );
 }
\ No newline at end of file
diff --git a/internal-api/js/admin-ticket.js b/internal-api/js/admin-ticket.js
index 1364337c..81ae9c8a 100644
--- a/internal-api/js/admin-ticket.js
+++ b/internal-api/js/admin-ticket.js
@@ -20,14 +20,17 @@ $(document).ready(function() {
 
     $editableDueDateContainer.find('#submit').click(function() {
         var newDueDate = $editableDueDateContainer.find('input[type="text"][name="due-date"]').val();
+        var ticketId = $('input[type="hidden"][name="orig_id"]').val();
         $.ajax({
             method: 'POST',
-            url: heskPath + 'internal-api/admin/calendar/',
-            data: {
-                trackingId: $('input[type="hidden"][name="track"]').val(),
-                action: 'update-ticket',
-                dueDate: newDueDate
+            url: heskPath + 'api/v1/staff/tickets/' + ticketId + '/due-date',
+            headers: {
+                'X-Internal-Call': true,
+                'X-HTTP-Method-Override': 'PATCH'
             },
+            data: JSON.stringify({
+                dueDate: newDueDate === '' ? null : newDueDate
+            }),
             success: function() {
                 mfhAlert.success(mfhLang.text('ticket_due_date_updated'));
                 $readonlyDueDateContainer.find('span#due-date').text(newDueDate == '' ? $('#lang_none').text() : newDueDate);
diff --git a/internal-api/js/manage-categories.js b/internal-api/js/manage-categories.js
index 5ea1ad59..e91836fb 100644
--- a/internal-api/js/manage-categories.js
+++ b/internal-api/js/manage-categories.js
@@ -268,7 +268,7 @@ function bindFormSubmit() {
         var foregroundColor = $modal.find('input[name="foreground-color"]').val();
         var manager = parseInt($modal.find('select[name="manager"]').val());
         var data = {
-            autoassign: $modal.find('input[name="autoassign"]').val() === 'true',
+            autoassign: $modal.find('input[name="autoassign"]:checked').val() === '1',
             backgroundColor: $modal.find('input[name="background-color"]').val(),
             description: $modal.find('textarea[name="description"]').val(),
             displayBorder: $modal.find('input[name="display-border"]:checked').val() === '1',