missing network protocols prevent access to shared folder

From one of my Windows 10 machines I am unable to access the shared folders on the other. The troubleshooter says "One or more network protocols are missing on this computer" and "Windows Sockets registry entries required for network connectivity are missing." Does anyone have any ideas?

I have run sfc /scannow, but no problems were found. I don't get the problem when sharing in the other direction or when accessing the shared folders on the same machine.

This comes amidst a cluster of sharing-related problems. Before the reboot after which the present problem manifested itself, shares going in the other direction were invisible in the network browser (but could be accessed via the search bar). Also, the machine in question does not appear in the HomeGroup browser even though it is a member of the HomeGroup.

Thanks for your suggestion. Strangely though, the problem seems to have corrected itself (without even a reboot, although I had rebooted several times previously in my attempts to solve it). But I will try your suggestion if I continue to have further weird SMB problems in the future.