Index: src/wp-admin/update-core.php
===================================================================
--- src/wp-admin/update-core.php	(revision 29719)
+++ src/wp-admin/update-core.php	(working copy)
@@ -242,10 +242,10 @@
 	foreach ( (array) $plugins as $plugin_file => $plugin_data) {
 		$info = plugins_api('plugin_information', array('slug' => $plugin_data->update->slug ));
 		// Get plugin compat for running version of WordPress.
-		if ( isset($info->tested) && version_compare($info->tested, $cur_wp_version, '>=') ) {
+		if ( isset( $info->tested ) && version_compare( $info->tested, $cur_wp_version, '>=' ) ) {
 			$compat = '<br />' . sprintf(__('Compatibility with WordPress %1$s: 100%% (according to its author)'), $cur_wp_version);
-		} elseif ( isset($info->compatibility[$cur_wp_version][$plugin_data->update->new_version]) ) {
-			$compat = $info->compatibility[$cur_wp_version][$plugin_data->update->new_version];
+		} elseif ( isset( $info->compatibility ) && isset( $info->compatibility[ $cur_wp_version ][ $plugin_data->update->new_version ] ) ) {
+			$compat = $info->compatibility[ $cur_wp_version ][ $plugin_data->update->new_version ];
 			$compat = '<br />' . sprintf(__('Compatibility with WordPress %1$s: %2$d%% (%3$d "works" votes out of %4$d total)'), $cur_wp_version, $compat[0], $compat[2], $compat[1]);
 		} else {
 			$compat = '<br />' . sprintf(__('Compatibility with WordPress %1$s: Unknown'), $cur_wp_version);
@@ -252,8 +252,8 @@
 		}
 		// Get plugin compat for updated version of WordPress.
 		if ( $core_update_version ) {
-			if ( isset($info->compatibility[$core_update_version][$plugin_data->update->new_version]) ) {
-				$update_compat = $info->compatibility[$core_update_version][$plugin_data->update->new_version];
+			if ( isset( $info->compatibility ) && isset( $info->compatibility[ $core_update_version ][ $plugin_data->update->new_version ] ) ) {
+				$update_compat = $info->compatibility[ $core_update_version ][ $plugin_data->update->new_version ];
 				$compat .= '<br />' . sprintf(__('Compatibility with WordPress %1$s: %2$d%% (%3$d "works" votes out of %4$d total)'), $core_update_version, $update_compat[0], $update_compat[2], $update_compat[1]);
 			} else {
 				$compat .= '<br />' . sprintf(__('Compatibility with WordPress %1$s: Unknown'), $core_update_version);