diff --git a/CHANGELOG.md b/CHANGELOG.md
index 705ea5ec..d2839694 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# v1.8.14
+## mm/dd/2018
+
+1. [](#bugfix)
+    * Fixed Grav core update potentially spinning forever because of an error which happens after a successful upgrade
+
 # v1.8.13
 ## 11/05/2018
 
diff --git a/classes/adminbasecontroller.php b/classes/adminbasecontroller.php
index 1bcac15d..ff584ed3 100644
--- a/classes/adminbasecontroller.php
+++ b/classes/adminbasecontroller.php
@@ -202,6 +202,29 @@ class AdminBaseController
         $this->redirectCode = $code;
     }
 
+    /**
+     * Sends JSON response and terminates the call.
+     *
+     * @param array $response
+     * @param int $code
+     * @return bool
+     */
+    protected function sendJsonResponse(array $response, $code = 200)
+    {
+        // Make sure nothing extra gets written to the response.
+        while (ob_get_level()) {
+            ob_end_clean();
+        }
+
+        // JSON response.
+        http_response_code($code);
+        header('Content-Type: application/json');
+        header('Cache-Control: no-cache, no-store, must-revalidate');
+
+        echo json_encode($response);
+        exit();
+    }
+
     /**
      * Handles ajax upload for files.
      * Stores in a flash object the temporary file and deals with potential file errors.
diff --git a/classes/admincontroller.php b/classes/admincontroller.php
index 4e0932e2..44df48e0 100644
--- a/classes/admincontroller.php
+++ b/classes/admincontroller.php
@@ -466,7 +466,7 @@ class AdminController extends AdminBaseController
     /**
      * Handles updating Grav
      *
-     * @return bool True if the action was performed
+     * @return bool False if user has no permissions.
      */
     public function taskUpdategrav()
     {
@@ -479,14 +479,14 @@ class AdminController extends AdminBaseController
         $result  = Gpm::selfupgrade();
 
         if ($result) {
-            $this->admin->json_response = [
+            $json_response = [
                 'status'  => 'success',
                 'type'    => 'updategrav',
                 'version' => $version,
                 'message' => $this->admin->translate('PLUGIN_ADMIN.GRAV_WAS_SUCCESSFULLY_UPDATED_TO') . ' ' . $version
             ];
         } else {
-            $this->admin->json_response = [
+            $json_response = [
                 'status'  => 'error',
                 'type'    => 'updategrav',
                 'version' => GRAV_VERSION,
@@ -494,7 +494,7 @@ class AdminController extends AdminBaseController
             ];
         }
 
-        return true;
+        return $this->sendJsonResponse($json_response);
     }
 
     /**
@@ -923,11 +923,13 @@ class AdminController extends AdminBaseController
             } catch (\Exception $e) {
                 $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
 
-                return;
+                return false;
             }
         }
 
         $this->admin->json_response = ['status' => 'success', 'feed_data' => $feed_data];
+
+        return true;
     }
 
     /**
@@ -971,12 +973,17 @@ class AdminController extends AdminBaseController
                 ];
             } else {
                 $this->admin->json_response = ['status' => 'error', 'message' => 'Cannot connect to the GPM'];
+
+                return false;
             }
 
         } catch (\Exception $e) {
             $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
+
+            return false;
         }
 
+        return true;
     }
 
     /**
@@ -994,7 +1001,7 @@ class AdminController extends AdminBaseController
             //No notifications cache (first time)
             $this->admin->json_response = ['status' => 'success', 'notifications' => [], 'need_update' => true];
 
-            return;
+            return true;
         }
 
         $need_update = false;
@@ -1011,7 +1018,7 @@ class AdminController extends AdminBaseController
         } catch (\Exception $e) {
             $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
 
-            return;
+            return false;
         }
 
         $this->admin->json_response = [
@@ -1019,6 +1026,8 @@ class AdminController extends AdminBaseController
             'notifications' => $notifications,
             'need_update'   => $need_update
         ];
+
+        return true;
     }
 
     /**
@@ -1181,8 +1190,8 @@ class AdminController extends AdminBaseController
                 'status'  => 'error',
                 'message' => $this->admin->translate('PLUGIN_ADMIN.INSUFFICIENT_PERMISSIONS_FOR_TASK')
             ];
-            echo json_encode($json_response);
-            exit;
+
+            return $this->sendJsonResponse($json_response, 403);
         }
 
         //check if there are packages that have this as a dependency. Abort and show which ones
@@ -1197,8 +1206,8 @@ class AdminController extends AdminBaseController
             }
 
             $json_response = ['status' => 'error', 'message' => $message];
-            echo json_encode($json_response);
-            exit;
+
+            return $this->sendJsonResponse($json_response, 200);
         }
 
         try {
@@ -1206,8 +1215,8 @@ class AdminController extends AdminBaseController
             $result       = Gpm::uninstall($package, []);
         } catch (\Exception $e) {
             $json_response = ['status' => 'error', 'message' => $e->getMessage()];
-            echo json_encode($json_response);
-            exit;
+
+            return $this->sendJsonResponse($json_response, 200);
         }
 
         if ($result) {
@@ -1216,16 +1225,16 @@ class AdminController extends AdminBaseController
                 'dependencies' => $dependencies,
                 'message'      => $this->admin->translate(is_string($result) ? $result : 'PLUGIN_ADMIN.UNINSTALL_SUCCESSFUL')
             ];
-            echo json_encode($json_response);
-            exit;
+
+            return $this->sendJsonResponse($json_response, 200);
         }
 
         $json_response = [
             'status'  => 'error',
             'message' => $this->admin->translate('PLUGIN_ADMIN.UNINSTALL_FAILED')
         ];
-        echo json_encode($json_response);
-        exit;
+
+        return $this->sendJsonResponse($json_response, 200);
     }
 
     /**
@@ -1245,8 +1254,8 @@ class AdminController extends AdminBaseController
                 'status'  => 'error',
                 'message' => $this->admin->translate('PLUGIN_ADMIN.INSUFFICIENT_PERMISSIONS_FOR_TASK')
             ];
-            echo json_encode($json_response);
-            exit;
+
+            $this->sendJsonResponse($json_response, 403);
         }
 
         $url = "https://getgrav.org/download/{$type}s/$slug/$current_version";
@@ -2251,6 +2260,8 @@ class AdminController extends AdminBaseController
 
         $admin_route = $this->admin->base;
         $this->setRedirect('/' . $language . $admin_route . '/' . $redirect);
+
+        return true;
     }
 
     /**