diff --git a/wp-ffpc-abstract.php b/wp-ffpc-abstract.php
index 563b358..e835877 100644
--- a/wp-ffpc-abstract.php
+++ b/wp-ffpc-abstract.php
@@ -65,7 +65,7 @@ if (!class_exists('WP_Plugins_Abstract')) {
 		protected $donation_link;
 		protected $button_save;
 		protected $button_delete;
-		protected $capability = 10;
+		protected $capability = 'manage_options';
 		protected $donation_business_name;
 		protected $donation_item_name;
 		protected $broadcast_message;
diff --git a/wp-ffpc-acache.php b/wp-ffpc-acache.php
index 17cd914..6428f8c 100644
--- a/wp-ffpc-acache.php
+++ b/wp-ffpc-acache.php
@@ -96,14 +96,14 @@ foreach ( $wp_ffpc_keys as $internal => $key ) {
 }
 
 /* serve cache 404 status */
-if ( $wp_ffpc_values['meta']['status'] == 404 ) {
+if ( isset( $wp_ffpc_values['meta']['status'] ) &&  $wp_ffpc_values['meta']['status'] == 404 ) {
 	header("HTTP/1.1 404 Not Found");
 	flush();
 	die();
 }
 
 /* server redirect cache */
-if ( $wp_ffpc_values['meta']['redirect'] ) {
+if ( isset( $wp_ffpc_values['meta']['redirect'] ) && $wp_ffpc_values['meta']['redirect'] ) {
 	header('Location: ' . $wp_ffpc_values['meta']['redirect'] );
 	flush();
 	die();
diff --git a/wp-ffpc-class.php b/wp-ffpc-class.php
index 0ec75fc..ed61cb5 100644
--- a/wp-ffpc-class.php
+++ b/wp-ffpc-class.php
@@ -264,7 +264,7 @@ if ( ! class_exists( 'WP_FFPC' ) ) {
 			/**
 			 * if options were saved, display saved message
 			 */
-			if (isset($_GET[ self::key_precache ]) && $_GET[ self::key_precache ]=='true' || $this->status == 4) : ?>
+			if ( ( isset($_GET[ self::key_precache ]) && $_GET[ self::key_precache ]=='true' ) || $this->status == 4) : ?>
 			<div class='updated settings-error'><p><strong><?php _e( 'Precache process was started, it is now running in the background, please be patient, it may take a very long time to finish.' , $this->plugin_constant ) ?></strong></p></div>
 			<?php endif;
 
@@ -582,7 +582,7 @@ if ( ! class_exists( 'WP_FFPC' ) ) {
 				<legend><?php _e( 'Precache', $this->plugin_constant ); ?></legend>
 				<dl>
 					<dt>
-						<?php if ( $_GET[ self::key_precache_disabled ]=='true' || $this->status == 5 || $this->shell_function == false ) : ?>
+						<?php if ( isset( $_GET[ self::key_precache_disabled ] ) && $_GET[ self::key_precache_disabled ] =='true' || $this->status == 5 || $this->shell_function == false ) : ?>
 							<strong><?php _e( "Precache functionality is disabled due to unavailable system call function. <br />Since precaching may take a very long time, it's done through a background CLI process in order not to run out of max execution time of PHP. Please enable one of the following functions if you whish to use precaching: " , $this->plugin_constant ) ?><?php echo join( ',' , $this->shell_possibilities ); ?></strong>
 						<?php else: ?>
 							<input class="button-secondary" type="submit" name="<?php echo $this->button_precache ?>" id="<?php echo $this->button_precache ?>" value="<?php _e('Pre-cache', $this->plugin_constant ) ?>" />