WD My Cloud App Version 4.1.1
I’m not understanding how you are trying to use scansnap with the EX2 My Cloud app. First of all, based on what ScanSnap’s website shows, all the apps you are scanning to, also qualify for file destinations. They hold and organize files based on preset locations on a computer. And Dropbox is nothing more than a secure file share you can access remotely. And from watching the tutorial, you need to be on the same local network to do what Scan Snap does.
The My Cloud desktop app is really only for connecting you remotely to the My Cloud EX2. You can then access the share folders on the remote EX2. It’s no wonder it was crashing on you, the app isn’t capable of doing anything with a file without being told what to do. It will not automatically upload a file to the EX 2 by pointing Scan Snap to it.
If you are looking to automatically upload files to the EX2, you will need to be on the local network, then point the Scan Snap to the share folder you want to put your files in. Then it should work for you. Just picking the app won’t work. As long as the device recognizes share folders, you should be fine.