Trying to copy or transfer photos on my iMac to My Cloud

I recently bought a My Cloud so that I can copy or transfer the photos (mostly of my now 11 year old daughter) from my 2010 iMac. I cannot seem to find a way to do it, I thought it would be easy but it appears not to be. When I look at the devices shown in finder, I can see My Cloud but when I try to connect to it, it asks for a username and password but neither the iMac user/password or the My Cloud user/password works. I know I’m a techcretin, help!


Have you looked at and read the User Manual?

User Manual: My Cloud Home and My Cloud Home Duo (

I have, just looked again and it could be that my iMac has El Capitan OSX which may not be compatible with My Cloud?