Being visible in a browsing list and being reachable are two different things, and the list is the unreliable one. Try the machine’s address directly first, because that separates a discovery problem from an actual connection problem.
The first thing to establish is which of two very different problems you have.
Reachable, or merely invisible?
Connect to the enclosure by its address rather than by looking for it in a list — typed into a file manager as a network path, or opened as a management page in a browser.
If that works, the enclosure is reachable and the problem is discovery. That is a nuisance rather than a fault, and the practical fix is to stop relying on the list: map the share by address so it is always there.
If that does not work, it is a connection problem, and the list was never going to help.
When it is a discovery problem
Browsing lists on a home network are built by announcement mechanisms that are less robust than people assume. Several things disturb them.
The network profile on the machine. Many operating systems restrict discovery on a network marked as public, and a network can be marked public without anybody choosing it.
A firewall on the machine blocking the discovery traffic while allowing the file sharing itself.
Older protocols disabled. Some sharing mechanisms that once handled discovery have been switched off by default on security grounds, and an enclosure relying on them disappears from the list while remaining perfectly reachable.
Different workgroups or naming domains between the machine and the enclosure.
Wireless isolation. Some routers and guest networks stop devices on the wireless side from talking to each other at all — which produces the specific symptom of a machine that can reach the internet and nothing on its own network.
When it is a connection problem
Is the enclosure on? Its own indicators, and whether it responds on its management page from any device.
Is it on the same network? A device on a guest network is deliberately separated from everything else, and this is a surprisingly common cause after somebody reconnects to the wrong name.
Has its address changed? An enclosure left on automatic addressing can be given a different address after a power cut, which breaks every mapping that referred to the old one. This is the argument for a reservation on the router.
Are the credentials still valid? Saved credentials go stale after a password change, and the failure often looks like a machine that cannot be found rather than one that refuses you.
Both ends of the cable, if it is wired, and whether the link came up at all.
After it works again
Map the share by address rather than by browsing, so the discovery mechanism is never in the path again.
Give the enclosure a fixed address, by reservation on the router, so that the address you mapped stays true.
And write down what the address is. The next time this happens will be a while from now, and the list will be no more reliable then than it is today.
The questions that come up before an order
It works from one computer and not another. What does that mean?
That the enclosure and the network are fine and the difference is in the machine that cannot reach it. Look at that machine’s firewall, its network profile — many systems restrict discovery on a network marked as public — and the credentials it has saved, which may be stale.
Why does the enclosure appear and then vanish from the list?
Browsing lists are built from announcements that arrive periodically and expire, so an entry appearing and disappearing is normal behaviour for a fragile mechanism rather than a sign the machine is going away. If the address works consistently while the list flickers, nothing is actually wrong with the connection.
Last reviewed 10 September 2026