If you've copied the files from 1.17.2 there should be no files from 1.10.1 used by the new install that haven't been upgraded to php8.
Take a look in your webserver error log to see if there is an error.
Also make sure that you have copied the .htaccess file across and that your server is set up correctly to use it.
You don't say what OS your server is running for what webserver nor the text of the error message. That will help diagnose the problem
