After creating the course, when you try to add files/folders in the course you will get an error "ERROR: Could not find or create a directory (/home/username/public_html/uploaddata/16"
This is due permission/ownership issue/.
Make sure that all your files and folders are having correct ownership (username:username)
Check the permission for /uploaddata/, this should be set to 777.
It's probably ON in your site.
If it is a shared host, you must ask your provider to switch it off...
