I discovered that my two remote disks cannot be seen on my W10 laptop, nor my elementary OS laptop. I fixed this by rebooting the disks which are connected to the network via an RJ45/USB connector to a BT Home Hub. This should work better than that. Here are my notes. …

Given this is seen on two laptops, with two disks units, via two connector technologies, the problem ought to be the hub. Although I found this on Microsoft’s community site. This post on the BT Community site, refers to a BT HH3 but points out that the log is visible. Best check it out next time it fails.