diff --git a/wp-admin/theme-install.php b/wp-admin/theme-install.php
index eb956f4380..dd9ff500d1 100644
--- a/wp-admin/theme-install.php
+++ b/wp-admin/theme-install.php
@@ -28,6 +28,11 @@ if ( ! is_network_admin() ) {
 }
 
 $installed_themes = search_theme_directories();
+
+if ( false === $installed_themes ) {
+	$installed_themes = array();
+}
+
 foreach ( $installed_themes as $k => $v ) {
 	if ( false !== strpos( $k, '/' ) ) {
 		unset( $installed_themes[ $k ] );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a192803ea8..8ef2be3b8b 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40635';
+$wp_version = '4.8-alpha-40636';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.