It would be very very unusual to set htdocs entirely to 777. It looks like something else is amiss here, as you are getting EX0 rather than a permission error
We would need to look further into this for you, however the access details on file appear to be incorrect or missing. Could you please update these details by visiting your client area, selecting the relevant purchase, then clicking "Review/Update Access Information" under the "Stored Access Information" section.
We look forward to further assisting you.