What is the EXACT error message you see? Can you post a screen capture of it?
Windows 10 has a variety of issues, the main issue was resolved with the Microsoft Windows 10 update published in early March. So make sure your Windows 10 PC is up to date with Windows 10 updates. See the following thread which has several workarounds to certain Windows 10 issues:
https://community.wd.com/t/compilation-of-windows-10-methods-steps-and-solutions/142576
If you have mapped Shares from the My Cloud to the Windows computer, It is not uncommon to see an alert message when the Windows computer first boots into Windows about not being able reconnect to the mapped Share. This (I assume) happens because the Windows tried to reconnect the mapped Share before the network stack (WiFi or Etherent) for Windows was loaded.
