I have a Buffalo 1 TB drive connected over Ethernet. Using Windows Explorer, I selected a directory X from C: drive, tried to copy and paste it into a directory to a directory on NAS. It created just the top level directory X, but did not copy any files under directory X. When I repeated the same operation, it copied all the files under X, probably because directory X was already created on X. If I try to copy and paste multiple directories at a time to NAS, only first directory gets created, nothing gets copied.

All the above operations work fine when copied elsewhere on the local hard drive. I started the good old command.com command prompt and used 'xcopy /s /e'. That worked fine and copied entire directory tree structure to NAS. I have been using this NAS from XP, Win7 and Vista. They all are able to do the above operations just fine.

Any idea why Win8.1 explorer would fail to copy directory and all its contents in one shot? 

Hello doteleven802,

Do you see the process bar and any error messages when you perform the first copy?

Please try to create a share folder from other computer, and then try to copy directory to the share folder and check if the issue still exists.
If you can normally copy to share folder, the issue may be related to configuration in the NAS. Please check.

If you have the same issue when you use the share folder, please use network monitor to capture the network traffic and share it with us in OneDrive.
Microsoft Network Monitor 3.4
http://www.microsoft.com/en-us/download/details.aspx?id=4865

Best regards,
Fangzhou CHEN

I confirm : everyone on the planet is getting the same issue : from windows 8.1 to a NAS : doesn't copy without message, just creates silently the first folder and leave it empty.

every other combination works : from windows 7 to the same NAS, windows 8.1 to an USB key, everything works.

for your information, a NAS is a standalone device, not a computer, you can only manage it remotely.

so just stop asking about details about the error message, there isn't any.

this is not something you can fix by making settings or reading KB. you have to make the test yourself if you don't believe your customers, and once you'll understand that this is a serious bug, you have to escalate to the development teams to alter the windows 8 code to make it work almost as well as a windows 7 can.

pardon me if i speak hardly, but i've just made a dozen of internet searches, and the whole platet seems to be aware of this issue, you are the only one who ignores it or ask an unrelated question. on another hand, your are the ony ones that can fix it. Don't try to incriminate the NAS firmware as you were able to deal with it in windows 7.

if you need more info, just make an internet search with the following terms :

"windows 8.1" when copying on a "network drive" nas