diff --git a/wp-includes/version.php b/wp-includes/version.php
index 8a3216045f..b15415ce37 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.9-alpha-60731';
+$wp_version = '6.9-alpha-60732';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
diff --git a/wp-includes/widgets.php b/wp-includes/widgets.php
index 6bc1ffc6f7..5bf9d16b31 100644
--- a/wp-includes/widgets.php
+++ b/wp-includes/widgets.php
@@ -1350,6 +1350,13 @@ function retrieve_widgets( $theme_changed = false ) {
 	$sidebars_widgets = _wp_remove_unregistered_widgets( $sidebars_widgets, $registered_widgets_ids );
 	$sidebars_widgets = wp_map_sidebars_widgets( $sidebars_widgets );
 
+	// Replace non-array values inside the array with an empty array.
+	foreach ( $sidebars_widgets as $key => $value ) {
+		if ( ! is_array( $value ) ) {
+			$sidebars_widgets[ $key ] = array();
+		}
+	}
+
 	// Find hidden/lost multi-widget instances.
 	$shown_widgets = array_merge( ...array_values( $sidebars_widgets ) );
 	$lost_widgets  = array_diff( $registered_widgets_ids, $shown_widgets );
@@ -1511,6 +1518,13 @@ function wp_map_sidebars_widgets( $existing_sidebars_widgets ) {
 
 		$old_sidebars_widgets = _wp_remove_unregistered_widgets( $old_sidebars_widgets );
 
+		// Replace non-array values inside the array with an empty array.
+		foreach ( $new_sidebars_widgets as $key => $value ) {
+			if ( ! is_array( $value ) ) {
+				$new_sidebars_widgets[ $key ] = array();
+			}
+		}
+
 		if ( ! empty( $old_sidebars_widgets ) ) {
 
 			// Go through each remaining sidebar...