Index: src/wp-includes/general-template.php
===================================================================
--- src/wp-includes/general-template.php	(revision 47302)
+++ src/wp-includes/general-template.php	(working copy)
@@ -3726,7 +3726,7 @@
 			$settings['codemirror'],
 			array(
 				'mode'              => 'css',
-				'lint'              => true,
+				'lint'              => false,
 				'autoCloseBrackets' => true,
 				'matchBrackets'     => true,
 			)