I want to have a website structure like this example.com/ - homepage example.com/solutions/ - this will be the solution parent page example.com/solutions/solution-one - child solution page example.com/solutions/solution-two- child solution page

i have setup the example.com/solutions/index.html file so it can be opened as a parent page, but is shows me an error You don't have permission to access /solutions/.html on this server.

What is the problem to this, how can i open parent, directory page? I na just using regular html pages, no cms or anything...