Undefined server path error message

I have installed Mark Huot’s file-upload app, and the installation went fine. I uploaded the extension, the language file, and the icons. Then I enabled the extension and created a custom field group which includes the file upload feature. However, when I go to the Publish tab and select the template from the dropdown list, the field for the file says “You have not defined a server path in the Upload Settings”, when in fact there is a server path specified:

/Applications/MAMP/htdocs/ee/file_uploads

I am using FILE version ext.file_311.zip

I don’t think that this has anything to do with the fact that I am running MAMP on a Mac to develop the site, but Im not sure how to get it running. Any help is welcome.

Thanks,

Neal