New Install: Object not found on selection of menu item

I have just installed a new copy of Grav and I can display the home page without any issues. I follwed the instructions to add a new page but when I click the name from the menu bar on the home page I recieved an Object not found error message - The requested URL was not found on this server.

The home page is displayed under: localhost/grav/ but fails when calling: localhost/grav/mypage

Any suggestions?

I am running on a Windows 10 operating system. Using XAMPP and my development environment is Adobe Brackets.

Thanks.

Please follow this advice first: 404 NOT FOUND

Adding the AllowOverride All and changing the RewriteBase resolved my issue thanks.