Device Not Working Properly

i have 4TB Network hard drive (My Cloud) 

I am using that one on local network and its not working properly. before it was working but now not. when i open device on any computer it shows FOLDER IS EMPTY and i have important data inside almost 400Gb :( 

This is not enough information to start helping you.

What OS are you using?

On your LAN what are you using to view shares and their content?

Can you login to the Dashboard?

What happened from the time it was working properly until now? Firmware Update? Power Outage? Router Rebooted?

Have you tried a “System Only Restore”?

etc.

can you see the files through the mycloud desktop or mobil app?

Are you able to open the Dashboard and do a reboot? See image below.

Posted by,
cat0w (USA)