My Cloud working very slow or not at all

If your iMac is running El Capitan there are problems with that version of OS X and the My Cloud. If you have another computer available try transferring files to the My Cloud and see if the problem persists. You may also want to read through the following thread link if you haven’t done so already.

https://community.wd.com/t/before-you-pack-up-your-wd-and-return-it-lets-talk-about-copying-speeds/91887

Thread discussing some of the El Capitan issues.

https://community.wd.com/t/support-os-x-el-capitan/96744