HTTP 500 error on IIS

This is the first time I try Grav on IIS (I am a Linux user) and I get HTTP 500 error "The website cannot display the page" from Internet Explorer.

I already checked Internal Server Error doc, as well as Permission doc but they didn't help.

The server has PHP 7, URL Rewrite is already installed. PHP is running well. Grav's PHP requirements are also met. I also tried to give the server full control to the site's folder. No thing is in the server's log files.

I have no ideas what is going on. Any help is really appreciated!

Problem solved. The Grav's folder somehow was "encrypted" by Windows so IIS couldn't read it, after right-clicked on the folder name, unchecked "Encrypt blah blah blah...", deleted Grav's cache and the site ran.