TEMPLATE ERROR

Message: Unable to find template "about.html" (looked into: C:\xampp1\htdocs/template/KELTIR, C:\xampp1\htdocs/custom/plugins, C:\xampp1\htdocs/src/component/plugins).
File: C:\xampp1\htdocs\vendor\twig\twig\src\Loader\FilesystemLoader.php
Line: 227
Code: throw new LoaderError($this->errorCache[$name]);