Old NAS devices use SMBv1 for the network shares. Microsoft has removed SMBv1 since Windows 10 Update 1709. You can get more information here:
https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-by-default-in-windows. There is an easy fix for it.
- press the windows key
- type "windows features" and press enter
- it opens a new program
- scroll down until you see "SMB 1.0/CIFS File sharing support"
- check mark the box for all services and confirm
- it will require a restart, safe all work.