It is working after opening iCloud settings. Beachball came up for a bit, and the handoff icon popped up in the dock when it went away.It didn't work for me. Tried opening a page in Safari on iPhone, and creating a message.
No response from iMac with 10.11. Walked into the other room and set the phone next to Macbook Air running 10.10.x and it responded as expected.