ICloud Password prompt On my Yosemite OSX machine I often get an ICloud prompt after awaking from sleep or after a reboot like this



what program is causing this? Is it a valid Apple one or one trying to get my password?

I have not knowingly set an app-specific password.

and in normal use ie not just after awake I got the box again but a more interesting log

24/03/2016 11:51:12.488 identityservicesd[8431]: [Warning] Registration failed for Registration info (0x7ff8e1435230): [Registered: NO] [Type: AppleID] [Device Name: (null)] [Service Type: com.apple.private.alloy.maps] [Env: (null)] [Main ID: example@mac.com] [Phone Number: example@mac.com] [AppleID: example@mac.com] [UserID: E: example@mac.com] [C2K: NO] [Push Token: &lt;f72dd563 26eccf96 f9e058ca b26ff2b7 fa67c0e9 e7b8e17e a9c86f31 c8d5f217&gt;] [Region ID: R:GB] [Base Number: +440000000000] [URIs: ()] [Candidates: (example@mac.com, example@icloud.com, example@me.com)] [Auth Cert: 0x0] [Reg Cert: 0x0] [Profile ID: D:53092237] [Auth User ID: (null)] [Heartbeat Date: (null)]   (Error: 0)


From that list of contacts it does look message related but still what proof is that this is from Apple and note my Message does not work even if I provide a password(see other question)
You can try logging out your iCloud in Settings and logging in back again. I've had the same issue before when I changed some account settings on another device.

It's a legit prompt from OS X but I think it's a sync operation bug.