diff --git a/amp.php b/amp.php
index 76164b750c1..73b7aed5a79 100644
--- a/amp.php
+++ b/amp.php
@@ -5,7 +5,7 @@
  * Plugin URI: https://amp-wp.org
  * Author: AMP Project Contributors
  * Author URI: https://github.com/ampproject/amp-wp/graphs/contributors
- * Version: 1.1.1
+ * Version: 1.2-alpha
  * Text Domain: amp
  * Domain Path: /languages/
  * License: GPLv2 or later
@@ -14,108 +14,118 @@
  */
 
 /**
- * Print admin notice regarding having an old version of PHP.
+ * Errors encountered while loading the plugin.
  *
- * @since 0.7
+ * This has to be a global for the same of PHP 5.2.
+ *
+ * @var \WP_Error $_amp_load_errors
  */
-function _amp_print_php_version_admin_notice() {
-	?>
-	<div class="notice notice-error">
-		<p>
-			<?php
-			printf(
-				/* translators: %s: required PHP version */
-				esc_html__( 'The AMP plugin requires PHP %s. Please contact your host to update your PHP version.', 'amp' ),
-				'5.4+'
-			);
-			?>
-		</p>
-	</div>
-	<?php
-}
+global $_amp_load_errors;
+
+$_amp_load_errors = new \WP_Error();
+
 if ( version_compare( phpversion(), '5.4', '<' ) ) {
-	add_action( 'admin_notices', '_amp_print_php_version_admin_notice' );
-	return;
+	$_amp_load_errors->add(
+		'insufficient_php_version',
+		sprintf(
+			/* translators: %s: required PHP version */
+			__( 'The AMP plugin requires PHP %s. Please contact your host to update your PHP version.', 'amp' ),
+			'5.4+'
+		)
+	);
 }
 
-/**
- * Print admin notice regarding DOM extension is not installed.
- *
- * @since 1.0
- */
-function _amp_print_php_dom_document_notice() {
-	?>
-	<div class="notice notice-error">
-		<p>
-			<?php
-				printf(
-					/* translators: %s: PHP extension name */
-					esc_html__( 'The AMP plugin requires the %s extension in PHP. Please contact your host to install this extension.', 'amp' ),
-					'DOM'
-				);
-			?>
-		</p>
-	</div>
-	<?php
-}
-if ( ! class_exists( 'DOMDocument' ) ) {
-	add_action( 'admin_notices', '_amp_print_php_dom_document_notice' );
-	return;
+// See composer.json for this list.
+$_amp_required_extensions = array(
+	'curl',
+	'date',
+	'dom',
+	'iconv',
+	'libxml',
+	'spl',
+);
+$_amp_missing_extensions  = array();
+foreach ( $_amp_required_extensions as $_amp_required_extension ) {
+	if ( ! extension_loaded( $_amp_required_extension ) ) {
+		$_amp_missing_extensions[] = $_amp_required_extension;
+	}
 }
+if ( count( $_amp_missing_extensions ) > 0 ) {
+	foreach ( $_amp_missing_extensions as &$_amp_missing_extension ) {
+		$_amp_missing_extension = "<code>$_amp_missing_extension</code>"; // Not using array_map() w/ closure due to PHP 5.2 support.
+	}
 
-/**
- * Print admin notice regarding DOM extension is not installed.
- *
- * @since 1.0.1
- */
-function _amp_print_php_missing_iconv_notice() {
-	?>
-	<div class="notice notice-error">
-		<p>
-			<?php
-				printf(
-					/* translators: %s: PHP extension name */
-					esc_html__( 'The AMP plugin requires the %s extension in PHP. Please contact your host to install this extension.', 'amp' ),
-					'iconv'
-				);
-			?>
-		</p>
-	</div>
-	<?php
+	$_amp_load_errors->add(
+		'missing_extension',
+		sprintf(
+			/* translators: %s is list of missing extensions */
+			_n(
+				'The following PHP extension is missing: %s. Please contact your host to finish installation.',
+				'The following PHP extensions are missing: %s. Please contact your host to finish installation.',
+				count( $_amp_missing_extensions ),
+				'amp'
+			),
+			implode( ', ', $_amp_missing_extensions )
+		)
+	);
 }
-if ( ! function_exists( 'iconv' ) ) {
-	add_action( 'admin_notices', '_amp_print_php_missing_iconv_notice' );
-	return;
+unset( $_amp_required_extensions, $_amp_missing_extensions, $_amp_required_extension, $_amp_missing_extension );
+
+if ( ! file_exists( __DIR__ . '/vendor/autoload.php' ) || ! file_exists( __DIR__ . '/vendor/sabberworm/php-css-parser' ) || ! file_exists( __DIR__ . '/assets/js/amp-block-editor-toggle-compiled.js' ) ) {
+	$_amp_load_errors->add(
+		'build_required',
+		sprintf(
+			/* translators: %s: composer install && npm install && npm run build */
+			__( 'You appear to be running the AMP plugin from source. Please do %s to finish installation.', 'amp' ), // phpcs:ignore WordPress.Security.EscapeOutput
+			'<code>composer install && npm install && npm run build</code>'
+		)
+	);
 }
 
 /**
- * Print admin notice when composer install has not been performed.
+ * Displays an admin notice about why the plugin is unable to load.
  *
- * @since 1.0
+ * @since 1.1.2
+ * @global \WP_Error $_amp_load_errors
  */
-function _amp_print_build_needed_notice() {
+function _amp_show_load_errors_admin_notice() {
+	global $_amp_load_errors;
 	?>
 	<div class="notice notice-error">
 		<p>
-			<?php
-			printf(
-				/* translators: %s: composer install && npm install && npm run build */
-				__( 'You appear to be running the AMP plugin from source. Please do %s to finish installation.', 'amp' ), // phpcs:ignore WordPress.Security.EscapeOutput
-				'<code>composer install && npm install && npm run build</code>'
-			);
-			?>
+			<strong><?php esc_html_e( 'AMP plugin unable to initialize.', 'amp' ); ?></strong>
+			<ul>
+			<?php foreach ( array_keys( $_amp_load_errors->errors ) as $error_code ) : ?>
+				<?php foreach ( $_amp_load_errors->get_error_messages( $error_code ) as $message ) : ?>
+					<li>
+						<?php echo wp_kses_post( $message ); ?>
+					</li>
+				<?php endforeach; ?>
+			<?php endforeach; ?>
+			</ul>
 		</p>
 	</div>
 	<?php
 }
-if ( ! file_exists( __DIR__ . '/vendor/autoload.php' ) || ! file_exists( __DIR__ . '/vendor/sabberworm/php-css-parser' ) || ! file_exists( __DIR__ . '/assets/js/amp-block-editor-toggle-compiled.js' ) ) {
-	add_action( 'admin_notices', '_amp_print_build_needed_notice' );
+
+// Abort if dependencies are not satisfied.
+if ( ! empty( $_amp_load_errors->errors ) ) {
+	add_action( 'admin_notices', '_amp_show_load_errors_admin_notice' );
+	if ( defined( 'WP_CLI' ) && WP_CLI ) {
+		$messages = array( __( 'AMP plugin unable to initialize.', 'amp' ) );
+		foreach ( array_keys( $_amp_load_errors->errors ) as $error_code ) {
+			$messages = array_merge( $messages, $_amp_load_errors->get_error_messages( $error_code ) );
+		}
+		$message = implode( "\n * ", $messages );
+		$message = str_replace( array( '<code>', '</code>' ), '`', $message );
+		WP_CLI::warning( $message );
+	}
 	return;
 }
 
 define( 'AMP__FILE__', __FILE__ );
 define( 'AMP__DIR__', dirname( __FILE__ ) );
-define( 'AMP__VERSION', '1.1.1' );
+define( 'AMP__VERSION', '1.2-alpha' );
 
 /**
  * Print admin notice if plugin installed with incorrect slug (which impacts WordPress's auto-update system).
@@ -262,14 +272,11 @@ function amp_init() {
 	add_action( 'wp_loaded', 'amp_add_options_menu' );
 	add_action( 'wp_loaded', 'amp_admin_pointer' );
 	add_action( 'parse_query', 'amp_correct_query_when_is_front_page' );
+	add_action( 'admin_bar_menu', 'amp_add_admin_bar_view_link', 100 );
 
 	// Redirect the old url of amp page to the updated url.
 	add_filter( 'old_slug_redirect_url', 'amp_redirect_old_slug_to_new_url' );
 
-	if ( class_exists( 'Jetpack' ) && ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) && version_compare( JETPACK__VERSION, '6.2-alpha', '<' ) ) {
-		require_once AMP__DIR__ . '/jetpack-helper.php';
-	}
-
 	// Add actions for legacy post templates.
 	add_action( 'wp', 'amp_maybe_add_actions' );
 
diff --git a/includes/sanitizers/class-amp-nav-menu-toggle-sanitizer.php b/includes/sanitizers/class-amp-nav-menu-toggle-sanitizer.php
index af4eb43bf8b..0e8cd72e9d2 100644
--- a/includes/sanitizers/class-amp-nav-menu-toggle-sanitizer.php
+++ b/includes/sanitizers/class-amp-nav-menu-toggle-sanitizer.php
@@ -99,6 +99,11 @@ public function sanitize() {
 		$script_el->appendChild( $this->dom->createTextNode( wp_json_encode( $expanded ) ) );
 		$state_el->appendChild( $script_el );
 		$nav_el->parentNode->insertBefore( $state_el, $nav_el );
+		if ( 'body' === $nav_el->nodeName ) {
+			$nav_el->insertBefore( $state_el, $nav_el->firstChild );
+		} else {
+			$nav_el->parentNode->insertBefore( $state_el, $nav_el );
+		}
 
 		$button_on = sprintf( "tap:AMP.setState({ $state_id: ! $state_id })" );
 		$button_el->setAttribute( 'on', $button_on );
diff --git a/readme.md b/readme.md
index 480c52b421e..c0b4fcbf266 100644
--- a/readme.md
+++ b/readme.md
@@ -7,7 +7,7 @@ Enable AMP on your WordPress site, the WordPress way.
 **Contributors:** [automattic](https://profiles.wordpress.org/automattic), [xwp](https://profiles.wordpress.org/xwp), [google](https://profiles.wordpress.org/google), [westonruter](https://profiles.wordpress.org/westonruter), [ryankienstra](https://profiles.wordpress.org/ryankienstra), [batmoo](https://profiles.wordpress.org/batmoo), [stubgo](https://profiles.wordpress.org/stubgo), [albertomedina](https://profiles.wordpress.org/albertomedina), [tweetythierry](https://profiles.wordpress.org/tweetythierry), [joshuawold](https://profiles.wordpress.org/joshuawold), [postphotos](https://profiles.wordpress.org/postphotos)  
 **Tags:** [amp](https://wordpress.org/plugins/tags/amp), [mobile](https://wordpress.org/plugins/tags/mobile)  
 **Requires at least:** 4.9  
-**Tested up to:** 5.1  
+**Tested up to:** 5.2  
 **Stable tag:** 1.1.1  
 **License:** [GPLv2 or later](http://www.gnu.org/licenses/gpl-2.0.html)  
 **Requires PHP:** 5.4  
diff --git a/readme.txt b/readme.txt
index 13e9de444bc..972b3010be4 100644
--- a/readme.txt
+++ b/readme.txt
@@ -2,7 +2,7 @@
 Contributors: automattic, xwp, google, westonruter, ryankienstra, batmoo, stubgo, albertomedina, tweetythierry, joshuawold, postphotos
 Tags: amp, mobile
 Requires at least: 4.9
-Tested up to: 5.1
+Tested up to: 5.2
 Stable tag: 1.1.1
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html