Challenge
When booting with Recovery Media which is based on Microsoft Windows 10 Fall Creators Update or Microsoft Windows Server 1709, a connection attempt to CIFS shares fails with:
You can't connect to the file share because it's not secure. This share requires the obsolete SMB1 protocol, which is unsafe and could expose your system to attack.
Your system requires SMB2 or higher. For more info on resolving this issue, see: https://go.microsoft.com/fwlink/?linkid=852747
Cause
In Windows 10 Fall Creators Update and Windows Server, version 1709 (RS3), the Server Message Block version 1 (SMBv1) network protocol is no longer installed by default. It was superseded by SMBv2 and later protocols starting in 2007. Microsoft publicly deprecated the SMBv1 protocol in 2014.
Solution
Enable SMBv2 or SMBv3 feature on your NAS device.
More Information
https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-windows-10-and-windows-server-version-1709