Installation/Startup Issue with PHP 7 built-in server

No but you did have spaces which are replaced by the browser with %20

Thank you for your answer. I am not using spaces. I think, the browser has nothing to do with it. The problem could be in translating special characters like á/é/í/ó/ú in URL helper.

The real path is "/home/user/Skúška/ci4/public/", the URL is "http://localhost/test/ci4/public/".

Code:

Fatal error: Uncaught Error: Class 'CodeIgniter\Autoloader\FileLocator' not found in /home/user/Skúška/ci4/system/Config/BaseService.php:168 Stack trace: #0 /home/user/Skúška/ci4/system/Common.php(593): CodeIgniter\Config\BaseService::locator(true) #1 /home/user/Skúška/ci4/system/bootstrap.php(154): helper('url') #2 /home/user/Skúška/ci4/public/index.php(36): require('/home/user/Sk\xC3\xBA...') #3 {main} thrown in /home/user/Skúška/ci4/system/Config/BaseService.php on line 168

Look at this part: "require('/home/user/Sk\xC3\xBA...')". Again, there is no problem with CI3.