500 Internal Server Error

I am trying to install GRAV on a shared hosting. It is a subdomain.
I upload the zip files on my server. After extracting the files, when I try to install GRAV, I receive the following message:

"Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@files.ogrlegal.net and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request."

For your information: PHP Version - 5.5.29,

I tried with deleting/modifying the .htaccess file. But the message did not change.

Any Idea how can I install it?

Did you try all the problem solving steps in http://learn.getgrav.org/troubleshooting/internal-server-error . I’m pretty sure it has something to do with your server setup.

I am on shared hosting and don’t have access to server settings.

I tried to change the .htaccess file. But nothing is changing.