Index: wp-admin/includes/file.php
===================================================================
--- wp-admin/includes/file.php	(revision 45112)
+++ wp-admin/includes/file.php	(working copy)
@@ -460,7 +460,7 @@
 
 	// Ensure file is real.
 	if ( ! is_file( $real_file ) ) {
-		return new WP_Error( 'file_does_not_exist', __( 'No such file exists! Double check the name and try again.' ) );
+		return new WP_Error( 'file_does_not_exist', __( 'File does not exist! Please double check the name and try again.' ) );
 	}
 
 	// Ensure file extension is allowed.
Index: wp-admin/plugin-editor.php
===================================================================
--- wp-admin/plugin-editor.php	(revision 45112)
+++ wp-admin/plugin-editor.php	(working copy)
@@ -105,7 +105,7 @@
 	$editable_extensions = wp_get_plugin_file_editable_extensions( $plugin );
 
 if ( ! is_file( $real_file ) ) {
-	wp_die( sprintf( '<p>%s</p>', __( 'No such file exists! Double check the name and try again.' ) ) );
+	wp_die( sprintf( '<p>%s</p>', __( 'File does not exist! Please double check the name and try again.' ) ) );
 } else {
 	// Get the extension of the file
 	if ( preg_match( '/\.([^.]+)$/', $real_file, $matches ) ) {
Index: wp-admin/theme-editor.php
===================================================================
--- wp-admin/theme-editor.php	(revision 45112)
+++ wp-admin/theme-editor.php	(working copy)
@@ -272,7 +272,7 @@
 
 <?php
 if ( $error ) :
-	echo '<div class="error"><p>' . __( 'Oops, no such file exists! Double check the name and try again, merci.' ) . '</p></div>';
+	echo '<div class="error"><p>' . __( 'File does not exist! Please double check the name and try again.' ) . '</p></div>';
 else :
 	?>
 	<form name="template" id="template" action="theme-editor.php" method="post">