'Failed to connect to the device' message

I have no problem connecting to my EX4100 NAS on my main PC via the dashboard. However, when I try using a laptop that has the ‘WD Mycloud’ desktop app, it defaults to the ‘WDMycloud.com’ option. Below the panel is the message ‘Failed to connect to the device’(in red). If I log in to ‘.com’ a number of MYcloud devices are displayed. I choose the one that has the correct IP address for my device and I get dropped back to the login screen.
I am able to log in to the dashboard via the Windows network ‘MyCloud’ icon on the laptop.

My ISP is ‘talktalk’ and they have placed a blanket ban on remote access software. However this has been in place for some time and a friend who lives elsewhere but has been given access to my NAS has been able to connect. He is suddenly unable to connect to my NAS (using a Mac and the Mac version of the desktop app). He is forced to use the mycloud .com route (which works). I have recently installed the firmware update.

Hi HomeUserBob,

Unfortunately, My Cloud Desktop Application for Windows and macOS End of Life and is no longer supported to work with My Cloud firmware released after 03/2016. You may use MyCloud.com in a web browser or the My Cloud Mobile app for Android and iOS instead of My Cloud Desktop Application.