Can't access backup via dashboard

Disconnected WDMyCloud and then reconnected but not backing up now. When I open the dashboard and click on the PC icon, it comes up with a box to enter Workgroup login details. The backup taps are greyed out. What is that? Never seen it before, so no idea what this refers to.

Can open the drive via Explorer and via IP on chrome, and all seems fine, so just a problem with the dashboard app on Windows 10. Have reset device also and restarted computer but to no avail. Need some simple step-by-step help as not a computer wizard! Thanks.

An image of what you are seeing would help. Is this a 2nd generation My Cloud, Firmware 2.xx.xx?

Look at this and see if it helps. My Cloud: Configuring USB Backups

Tried all the usual things. Eventually used Troubleshooting in the W10 Control Panel and this solved it, but larger files took a long time to backup. I remember a thread about using the Register Edit to change some start value from a 2 to a 4 to overcome this problem, but couldn’t find the thread again. Really need an idiots guide as some problems aren’t with the WD smartware but the way it interacts with W10.