External drive connecting to DL-4100 not transferring files

[Feragui]

Do you have some anti-virus software installed and set to scan network drive, temporarily disable it, check if that is the cause.
Also try to map the network drive and then try the transfer again.
http://support.wdc.com/knowledgebase/answer.aspx?ID=2676

I also found this post on the forum that might help.

Error 0x8007003b and how I solved it

Since purchasing My Cloud Mirror, I had much difficulty with copying files from my laptop. I would consistently get “Error 0x8007003b - an unexpected network error occurred” using Windows 10. I also received a similar error on Windows 7 (same laptop, dual boot). To find out if it was my laptop or My Cloud, I copied the same folder (~7GB of photos in RAW format) to another PC in my house. It worked every time, so it must be My Cloud. After much research I didn’t find a solution, so I decided …