Your Dropbox is like a safe. SimpliWiki too needs the key to access it's content. To give SimpliWiki the key of the safe, please add an "email" and a "password" directive to YourOwnDropBox page. Note: your password will be stored in that page, it is stored "encrypted", so that nobody but us (or a thief) can use it. See HelpDirective and HelpSecurity.