Index: wp-admin/includes/class-wp-upgrader.php
===================================================================
--- wp-admin/includes/class-wp-upgrader.php	(revision 18575)
+++ wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -1351,9 +1351,20 @@
 
 		$install_actions = array(
 			'preview' => '<a href="' . $preview_link . '" class="thickbox thickbox-preview" title="' . esc_attr(sprintf(__('Preview &#8220;%s&#8221;'), $name)) . '">' . __('Preview') . '</a>',
-			'activate' => '<a href="' . $activate_link .  '" class="activatelink" title="' . esc_attr( sprintf( __('Activate &#8220;%s&#8221;'), $name ) ) . '">' . __('Activate') . '</a>'
-							);
+			'activate' => '<a href="' . $activate_link . '" class="activatelink" title="' . esc_attr( sprintf( __('Activate &#8220;%s&#8221;'), $name ) ) . '">' . __('Activate') . '</a>'
+		);
 
+		if( ! empty( $template ) ) {
+			global $wp_filesystem;
+			$themes_dir = $wp_filesystem->wp_themes_dir();
+			$template_data = get_theme_data( $themes_dir . $template . '/style.css' );
+
+			if( empty( $template_data[ 'Name' ] ) ) {
+				unset( $install_actions[ 'activate' ] ); 
+				echo sprintf( __( 'Unable to locate the required parent theme: <strong>%1$s</strong>.<br />You will need to install the parent theme before being able to activate this theme.' ) , $template );
+			}
+		}
+
 		if ( is_network_admin() && current_user_can( 'manage_network_themes' ) )
 			$install_actions['network_enable'] = '<a href="' . esc_url( wp_nonce_url( 'themes.php?action=enable&amp;theme=' . $template, 'enable-theme_' . $template ) ) . '" title="' . esc_attr__( 'Enable this theme for all sites in this network' ) . '" target="_parent">' . __( 'Network Enable' ) . '</a>';
 
@@ -1458,4 +1469,4 @@
 			$this->package = $uploads['basedir'] . '/' . $this->filename;
 		}
 	}
-}
\ No newline at end of file
+}