Config caching

Hi,
I am in process of trying to optimise performance of a CI4 project.
I have been watching a few PRs on Github over the last few months and followed the Config Caching with interest.
(https://github.com/codeigniter4/CodeIgniter4/pull/7696)
I have tried uncommenting the lines currently in the index.php file. However, when I uncomment these I get an error 500 message with no error reporting and nothing in the logs.
Is there anything extra I need to do to trial the config caching?
Luke

You need to delete the Config Cache:
https://codeigniter.com/user_guide/conce...fig-values

Regards, Frederik