diff --git a/CHANGELOG.md b/CHANGELOG.md
index 15d5e083..85e7c8e8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog for TGM Plugin Activation library
 
+## 2.5.2 (2015-07-15)
+* Hot Fix: fixes potential `Fatal error: Call to protected TGM_Plugin_Activation::__construct()` error and other compatibility issues when both TGMPA 2.5+ as well as TGMPA 2.3.6- would be loaded by different themes and plugins.
+
+Take note: We do **NOT** support 2.3.6 anymore and **_highly_** discourage its use. Any themes and plugins still using TGMPA 2.3.6 or less should upgrade as soon as possible. All the same, the end-user should not be confronted with white screens because of it, so this hot fix should prevent just that.
+
 ## 2.5.1 (2015-07-13)
 
 * Hot Fix: fixes potential `Fatal error: Call to undefined method TGM_Utils::validate_bool()` errors caused by a conflict with the Soliloquy plugin.
diff --git a/README.md b/README.md
index b54310b7..1f795d0a 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 
 **Lead Developers:**
 [Thomas Griffin](https://github.com/thomasgriffin) ([@jthomasgriffin](https://twitter.com/jthomasgriffin)), [Gary Jones](https://github.com/GaryJones) ([@GaryJ](https://twitter.com/GaryJ)), [Juliette Reinders Folmer](https://github.com/jrfnl) ([@jrf_nl](https://twitter.com/jrf_nl))  
-**Version:** 2.5.1  
+**Version:** 2.5.2 
 **Requires at least:** 3.7.0  
 **Tested up to:** 4.2.0  
 
diff --git a/class-tgm-plugin-activation.php b/class-tgm-plugin-activation.php
index 46d10c75..ee6eb730 100755
--- a/class-tgm-plugin-activation.php
+++ b/class-tgm-plugin-activation.php
@@ -8,7 +8,7 @@
  * or theme author for support.
  *
  * @package   TGM-Plugin-Activation
- * @version   2.5.1
+ * @version   2.5.2
  * @link      http://tgmpluginactivation.com/
  * @author    Thomas Griffin, Gary Jones, Juliette Reinders Folmer
  * @copyright Copyright (c) 2011, Thomas Griffin
@@ -18,7 +18,7 @@
  * Plugin Name: TGM Plugin Activation
  * Plugin URI:
  * Description: Plugin installation and activation for WordPress themes.
- * Version:     2.5.1
+ * Version:     2.5.2
  * Author:      Thomas Griffin, Gary Jones, Juliette Reinders Folmer
  * Author URI:  http://tgmpluginactivation.com/
  * Text Domain: tgmpa
@@ -66,7 +66,7 @@ class TGM_Plugin_Activation {
 		 *
 		 * @const string Version number.
 		 */
-		const TGMPA_VERSION = '2.5.1';
+		const TGMPA_VERSION = '2.5.2';
 
 		/**
 		 * Regular expression to test if a URL is a WP plugin repo URL.
@@ -149,7 +149,7 @@ class TGM_Plugin_Activation {
 		 *
 		 * @var string
 		 */
-		public $menu = 'tgmpa-install-plugins';
+		protected $menu = 'tgmpa-install-plugins';
 
 		/**
 		 * Parent menu file slug.
@@ -256,11 +256,15 @@ class TGM_Plugin_Activation {
 		 * Adds a reference of this object to $instance, populates default strings,
 		 * does the tgmpa_init action hook, and hooks in the interactions to init.
 		 *
+		 * @internal This method should be `protected`, but as too many TGMPA implementations
+		 * haven't upgraded beyond v2.3.6 yet, this gives backward compatibility issues.
+		 * Reverted back to public for the time being.
+		 *
 		 * @since 1.0.0
 		 *
 		 * @see TGM_Plugin_Activation::init()
 		 */
-		protected function __construct() {
+		public function __construct() {
 			// Set the current WordPress version.
 			$this->wp_version = $GLOBALS['wp_version'];
 
@@ -271,6 +275,34 @@ protected function __construct() {
 			add_action( 'init', array( $this, 'init' ) );
 		}
 
+		/**
+		 * Magic method to (not) set protected properties from outside of this class.
+		 *
+		 * @internal hackedihack... There is a serious bug in v2.3.2 - 2.3.6  where the `menu` property
+		 * is being assigned rather than tested in a conditional, effectively rendering it useless.
+		 * This 'hack' prevents this from happening.
+		 *
+		 * @see https://github.com/TGMPA/TGM-Plugin-Activation/blob/2.3.6/tgm-plugin-activation/class-tgm-plugin-activation.php#L1593
+		 *
+		 * @param string $name  Name of an inaccessible property.
+		 * @param mixed  $value Value to assign to the property.
+		 * @return void  Silently fail to set the property when this is tried from outside of this class context.
+		 *               (Inside this class context, the __set() method if not used as there is direct access.)
+		 */
+		public function __set( $name, $value ) {
+			return;
+		}
+
+		/**
+		 * Magic method to get the value of a protected property outside of this class context.
+		 *
+		 * @param string $name Name of an inaccessible property.
+		 * @return mixed The property value.
+		 */
+		public function __get( $name ) {
+			return $this->{$name};
+		}
+
 		/**
 		 * Initialise the interactions between this class and WordPress.
 		 *
@@ -1900,6 +1932,21 @@ function tgmpa( $plugins, $config = array() ) {
 		}
 
 		if ( ! empty( $config ) && is_array( $config ) ) {
+			// Send out notices for deprecated arguments passed.
+			if ( isset( $config['notices'] ) ) {
+				_deprecated_argument( __FUNCTION__, '2.2.0', 'The `notices` config parameter was renamed to `has_notices` in TGMPA 2.2.0. Please adjust your configuration.' );
+				if ( ! isset( $config['has_notices'] ) ) {
+					$config['has_notices'] = $config['notices'];
+				}
+			}
+
+			if ( isset( $config['parent_menu_slug'] ) ) {
+				_deprecated_argument( __FUNCTION__, '2.4.0', 'The `parent_menu_slug` config parameter was removed in TGMPA 2.4.0. In TGMPA 2.5.0 an alternative was (re-)introduced. Please adjust your configuration. For more information visit the website: http://tgmpluginactivation.com/configuration/#h-configuration-options.' );
+			}
+			if ( isset( $config['parent_url_slug'] ) ) {
+				_deprecated_argument( __FUNCTION__, '2.4.0', 'The `parent_url_slug` config parameter was removed in TGMPA 2.4.0. In TGMPA 2.5.0 an alternative was (re-)introduced. Please adjust your configuration. For more information visit the website: http://tgmpluginactivation.com/configuration/#h-configuration-options.' );
+			}
+
 			call_user_func( array( $instance, 'config' ), $config );
 		}
 	}
@@ -2697,9 +2744,9 @@ public function process_bulk_actions() {
 				}
 				unset( $slug, $name, $source );
 
-				// Create a new instance of TGM_Bulk_Installer.
-				$installer = new TGM_Bulk_Installer(
-					new TGM_Bulk_Installer_Skin(
+				// Create a new instance of TGMPA_Bulk_Installer.
+				$installer = new TGMPA_Bulk_Installer(
+					new TGMPA_Bulk_Installer_Skin(
 						array(
 							'url'          => esc_url_raw( $this->tgmpa->get_tgmpa_url() ),
 							'nonce'        => 'bulk-' . $this->_args['plural'],
@@ -2846,6 +2893,24 @@ protected function _get_plugin_data_from_name( $name, $data = 'slug' ) {
 	}
 }
 
+
+if ( ! class_exists( 'TGM_Bulk_Installer' ) ) {
+
+	/**
+	 * Hack: Prevent TGMPA v2.4.1- bulk installer class from being loaded if 2.4.1- is loaded after 2.5+.
+	 */
+	class TGM_Bulk_Installer {
+	}
+}
+if ( ! class_exists( 'TGM_Bulk_Installer_Skin' ) ) {
+
+	/**
+	 * Hack: Prevent TGMPA v2.4.1- bulk installer skin class from being loaded if 2.4.1- is loaded after 2.5+.
+	 */
+	class TGM_Bulk_Installer_Skin {
+	}
+}
+
 /**
  * The WP_Upgrader file isn't always available. If it isn't available,
  * we load it here.
@@ -2862,6 +2927,11 @@ protected function _get_plugin_data_from_name( $name, $data = 'slug' ) {
 	 * Load bulk installer
 	 */
 	function tgmpa_load_bulk_installer() {
+		// Silently fail if 2.5+ is loaded *after* an older version.
+		if ( ! isset( $GLOBALS['tgmpa'] ) ) {
+			return;
+		}
+
 		// Get TGMPA class instance.
 		$tgmpa_instance = call_user_func( array( get_class( $GLOBALS['tgmpa'] ), 'get_instance' ) );
 
@@ -2870,7 +2940,7 @@ function tgmpa_load_bulk_installer() {
 				require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
 			}
 
-			if ( ! class_exists( 'TGM_Bulk_Installer' ) ) {
+			if ( ! class_exists( 'TGMPA_Bulk_Installer' ) ) {
 
 				/**
 				 * Installer class to handle bulk plugin installations.
@@ -2881,12 +2951,14 @@ function tgmpa_load_bulk_installer() {
 				 * @since 2.2.0
 				 *
 				 * @internal Since 2.5.0 the class is an extension of Plugin_Upgrader rather than WP_Upgrader
+				 * @internal Since 2.5.2 the class has been renamed from TGM_Bulk_Installer to TGMPA_Bulk_Installer.
+				 *           This was done to prevent backward compatibility issues with v2.3.6.
 				 *
 				 * @package TGM-Plugin-Activation
 				 * @author  Thomas Griffin
 				 * @author  Gary Jones
 				 */
-				class TGM_Bulk_Installer extends Plugin_Upgrader {
+				class TGMPA_Bulk_Installer extends Plugin_Upgrader {
 					/**
 					 * Holds result of bulk plugin installation.
 					 *
@@ -3192,7 +3264,7 @@ public function auto_activate( $bool ) {
 				}
 			}
 
-			if ( ! class_exists( 'TGM_Bulk_Installer_Skin' ) ) {
+			if ( ! class_exists( 'TGMPA_Bulk_Installer_Skin' ) ) {
 
 				/**
 				 * Installer skin to set strings for the bulk plugin installations..
@@ -3202,13 +3274,17 @@ public function auto_activate( $bool ) {
 				 *
 				 * @since 2.2.0
 				 *
+				 * @internal Since 2.5.2 the class has been renamed from TGM_Bulk_Installer_Skin to
+				 *           TGMPA_Bulk_Installer_Skin.
+				 *           This was done to prevent backward compatibility issues with v2.3.6.
+				 *
 				 * @see https://core.trac.wordpress.org/browser/trunk/src/wp-admin/includes/class-wp-upgrader-skins.php
 				 *
 				 * @package TGM-Plugin-Activation
 				 * @author  Thomas Griffin
 				 * @author  Gary Jones
 				 */
-				class TGM_Bulk_Installer_Skin extends Bulk_Upgrader_Skin {
+				class TGMPA_Bulk_Installer_Skin extends Bulk_Upgrader_Skin {
 					/**
 					 * Holds plugin info for each individual plugin installation.
 					 *
diff --git a/example.php b/example.php
index 10e3b73f..064a6aab 100755
--- a/example.php
+++ b/example.php
@@ -10,7 +10,7 @@
  *
  * @package    TGM-Plugin-Activation
  * @subpackage Example
- * @version    2.5.1
+ * @version    2.5.2
  * @author     Thomas Griffin, Gary Jones, Juliette Reinders Folmer
  * @copyright  Copyright (c) 2011, Thomas Griffin
  * @license    http://opensource.org/licenses/gpl-2.0.php GPL v2 or later