WDMyCloud can't be opened because the original can't be found

I moved my MyCloud from one room to another and have been getting this since on my iMAC every time i try to connect to it from the shared folder in finder. My Macbook air works fine. There is another post on here -(closed) that says the answer is just to relaunch finder… well this doesn’t work for me at all.

i can use the go to server command and access it.
Also disconnecting from ethernet, turning wifi on - seems to work for a while.
Is this an El Capitain bug? it was working fine before i moved it - having said that it auto updated its firmware a few days ago so is it a firmware bug?.

Ive checked and the MyCloud has the same IP address as before. What I don’t get is the MBA on mavericks works fine but that just connects via wifi?

Any other options?

If this happened after moving the device to another room then there could be some latency issues involved. Are you able to share your router’s specifications?

yes no problem. my iMac is plugged directly into a BT home hub 5. this is cabled to a Netgear24 port unmanaged switch which the WDmycloud is now plugged into - the switch indicates the link is operating at Gigabit speed, It was plugged into another Netgear 5 port switch which is also directly linked to the BT home hub but is in a different room. the BT home hub is a modem.router.wifiAP from my UK ISP - its a common make and standard model in the UK.
happy to give more info

same message same set up only Virgin media superhub i have lost the blue light as well but! my Bluesound node still sees the device but i can not access it under Finder i have the

WDMyCloud” can’t be opened because the original item can’t be found. message