Hi, I've had a quick search on the web and believe to have found a couple of different solutions I'd like to try, it looks like it is to do with the file permissions, I'd love to chat more about your setup, like who your host is and find out the web server you are using, so I can try to help diagnose the problem.
These are the sort of jobs I like to take on because it helps me learn more about errors on the web so that in the future I'm better equipped to handle them. I have also quoted 2 days as with problems like this a lot of investigation needs to be done so I like to put a longer project length than other bidders would.
Thanks