Web server works until this line $bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $_SERVER)

[GrocExp]

I've been trying to pinpoint the exact point of failure with the installer setup utility. 

I've been able to get the index.php file to serve to the browser when I comment out the line $bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $_SERVER); and all lines following.

Attempting to leave this line uncommented leaves a 500 error on the browser and this error in the magento_error.log ...
proxy_fcgi:error] [pid 19212:tid 139802175330048] [client xxx.xx.xxx.xx:44384] AH01071: Got error 'Primary script unknown\n'

What I don't understand about the logic in the line causing the error.  I don't have any file path from the root of this computer that is at \Magento\Framework\App\Bootstrap.
I don't have any file path from the Magento folder on my web server.

Does this file attempt to create this space for writing or work space?  How can I set permissions for a file / folder path that does not exist and is created at run time?

[theMageComp]

Hello  @GrocExp 

Is it fresh Magento 2.3.3?
Did you ask hosting guys about this?

Is .htaccess file is proper?

And file permissions has proper permissions to run the Magento?

[GrocExp]

Thank you for being the one person to read and comment.

This is a clean install on CENTOS 8.  I've loaded all the software on this server myself.  There is a long list of items, if I can remember them all.  Firewall, apache, mysql, php, mysqladmin, GNOME, xrdp, text editior, etc...

I can get my <? PHP.Info file to work.  It shows all the information as expected.  On my original statement the page will load line by line until it trys to process $bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $_SER

I tried getting Composer to run in terminal.  I was able to fix a few extension issues, but right now I'm stuck with Composer with this error ...

the requested PHP extension pdo_mysql is missing from your system.

If you want me to dump my php.info screen to this chat, let me know.

[GrocExp]

I built this server myself.  It's not in a hosting environment.

I think the problem is I had mysql 8 installed.

I formatted the server and now I'm trying to re-build with CENTOS 8 and default MariaDB.

[GrocExp]

I'm still working on getting to the Magento setup program to work in the browser.  I've been trying to make this happen for months now.
I ran some com-pliancy tests and figured out I can not run php 7.4.  I spent some time to get back to php 7.3.
I was also able to get the Magento error to screen print this is what I currently see ...

Fatal error: Uncaught ReflectionException: Class Magento\Framework\App\ResourceConnection\Proxy does not exist in /var/www/html/Magento/vendor/magento/framework/Code/Reader/ClassReader.php:19 Stack trace: #0 /var/www/html/Magento/vendor/magento/framework/Code/Reader/ClassReader.php(19): ReflectionClass->__construct('Magento\\Framewo...') #1 /var/www/html/Magento/vendor/magento/framework/ObjectManager/Definition/Runtime.php(49): Magento\Framework\Code\Reader\ClassReader->getConstructor('Magento\\Framewo...') #2 /var/www/html/Magento/vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php(48): Magento\Framework\ObjectManager\Definition\Runtime->getParameters('Magento\\Framewo...') #3 /var/www/html/Magento/vendor/magento/framework/ObjectManager/ObjectManager.php(70): Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create('Magento\\Framewo...') #4 /var/www/html/Magento/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php(160): Magento\Framework\ObjectManager\ObjectManager->get('Magento\\F in /var/www/html/Magento/vendor/magento/framework/Code/Reader/ClassReader.php on line 19