We did some testing and this is an issue with the macApp store version. All software on the macApp store must be sandboxed, which restricts access the app has to portions of the computer drive.
This is why a folder in the location works OK, but a folder that is a link to another location does not. DataGraph does not have permission to “see” what is in that location.
FYI – Here is an article on sandboxing in case you’re interested.