The first user created using the automated setup is the administrator.
However, reading the new User Manual, I’m confused about the various accounts and passwords that are created using the automated setup process starting on p11, so I’m not surprised you’re having trouble…
I prefer to use the built-in setup proces as described on p16 onwards.
In the second dialogue box shown in p12, it asks for your first name, last name and ‘device user name’. It says this account will be the administrator account. I note that a password is created later, but I’m not sure if this is for the device, or for the MyCloud.com account. And other people have reported that they find this confusing…
You can clear the administrator password by performing a 4 second reset, described in p90 of the user manual. Once you have done this, you should be able to access the Dashboard with your ‘device user name’ and an empty password. If not, try ‘admin’ and no password.
The default device name is ‘wdmycloud’. Once you have access to the Dashboard, you can give it a new name. You will then be able to access it via this name. Essentially, this is the name of the computer running in the MyCloud device, as it appears in your local network (just like your Mac probably has a namename). It’s a way of simplifying network access without needing to remember IP addressesaddresses…
The other issues with ElCapitan are, I think, issues for Apple to sort out; it worked fine under Yosemite, but not so well under ElCap. What has changed? The Apple OS. Same situation with windows 10; it’s Microsoft’s problem.