initializeKint() undefined

I copied a CodeIgniter project running on another server into XAMPP to verify the operation, and the following error was displayed:

PHP Code:

Call to undefined method CodeIgniter\Autoloader\Autoloader::initializeKint() 


The backtrace is here:

PHP Code:

SYSTEMPATH\Boot.php : 56  —  CodeIgniter\Boot::initializeKint ()
FCPATH\index.php : 56  —  CodeIgniter\Boot::bootWeb ( arguments ) 


CI_VERSION is 4.1.1、and php version is 8.1.
Let me know if you need any other info.
thanks.

Your index.php and Boot.php are for CI v4.5.
If your CI version is 4.1.1, they are not compatible.

If you use PHP 8.1, CI 4.1.6 or later is required.
https://codeigniter.com/user_guide/chang...hancements

But it is always recommended to use the latest version, now v4.5.2.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

You copied vendor/ path?
Or system/ if installed from ZIP?

Simple CI 4 project for beginners codeigniter-expenses ( topic )

Thank you both for your replies.
I replaced the the app/Config folder, system folder and index.php in public folder with the CI4.1.6 one and fixed minor errors including #[\AllowDynamicProperties], so everything worked fine!
(I know it's best to go with the latest version...)

Thank you both so much.

CI v4.1 is very old. There are some Security Advisories:
https://github.com/codeigniter4/CodeIgni...advisories
Check your risk and upgrade if necessary.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper