Fatal error: Uncaught Error: Undefined constant "STDIN" in /home/matrixweb/public_html/whmcs2022/whmcs/vendor/symfony/process/Tests/PipeStdinInStdoutStdErrStreamSelect.php:17 Stack trace: #0 {main} thrown in /home/matrixweb/public_html/whmcs2022/whmcs/vendor/symfony/process/Tests/PipeStdinInStdoutStdErrStreamSelect.php on line 17