When the navigation item is saved with special characters, the user is unable to open the form. Upon clicking the item, an error is reported: “Due to either a session timeout or unauthorized access, you do not have permission to access this page.”
When you create a custom navigational link, if special characters are used such as /, \, &, #, %, they break the capability to redirect the user to a form or to an external link. Refrain from adding a special character. They must be omitted so that the form can be rendered.