Contao manager works in one directory but not a second

I have a dev directory of contao installed. The Conato-manager.php loads fine.
I have tried doing a fresh install, a copy and paste of the dev directory, but everything I do, I am getting this error:
PHP Command Line Interface
The PHP symlink method is unavailable or does not work correctly.
Failed to create "symbolic" link from "path\to\folder" to "C:\Windows\Temp\7925.tmp".

I have checked permissions, both folders are identical. I am using IIS. I have the authentication set to Administrator on both.
I can create symlinks in powershell by running php vendor/bin/contao-console contao:symlinks

I don't get it, especially because it works in a sibling folder, just not in the second folder.

I would try to configure the rights for creating symbolic links for your Windows user (e.g. with Polsedit, see https://docs.contao.org/manual/de/an...nde-maßnahmen)

Well now I am getting stuck at validating the PHP Binary. It works in one instance of contao, but not a second.
I'm getting a "Exit Code: 1(General error)"
Output:
Error Output:

Nothing in the error output though.

Why does it validate in one instance but not in second instance of Contao? Can there only be one instance at a time on a Windows server?

If I create a second site pointing to the directory where contao is working, the first one works, while the second one fails to validate the PHP Binary.
This makes absolutely no sense to me.
Is my copy of Windows corrupted?
I have identical permissions setup. Makes me want to move away from using Contao.

This certainly has nothing to do with Contao. Can you execute any PHP file (such as phpinfo())?

Just try another local web server stack such as XAMPP or Laragon.

Figured it out... Stupid IIS creates it's own Application Pools for every new site, however, when I remembered to change it to the DefaultAppPool now it works. So some IIS Microsoft annoyance.