Help using CMS

Hi there mates.

I'm trying to use CMS but i'm getting some little problems. I cannot set a folder URL that links to the content. It always show "Internal Error".

The Error Log in Service Center shows the following error:

"CMS_Backoffice - To get a list of contents, an existing Folder identifier or Path is required."

The URL of the folder is defined as:

Can anyone help?

Thanks a lot,
Pedro Domingues