Fatal error: Uncaught Error: Class "PHP_CodeSniffer\Files\File" not found in /var/www/html/upload/PhpSpreadsheet-master/vendor/squizlabs/php_codesniffer/src/Files/DummyFile.php:20 Stack trace: #0 {main} thrown in /var/www/html/upload/PhpSpreadsheet-master/vendor/squizlabs/php_codesniffer/src/Files/DummyFile.php on line 20