After installing El Capitan and a reboot the mbp is not able to logon to icloud. "Un unknown error occorred" is the only message.
Is anyone else having this problem. Login in from another device is no problem.
Logon error icloud
It seems to be a common issue. Logging out of iCloud in System Preferences fixed it for me. I had a residual issue with iCloud Mail not working, but going to Internet Accounts, iCloud, and deselecting, then reselecting Mail fixed it.
Each time I restart my desktop iMac, I get an error telling there's a problem with iCloud and asking that I fix it in SysPrefs, but it doesn't eem to impact anyting. And afert every restart, I have to do the deslect/reselect thing for iCloud Mail. I don't have any of these issues on my 13" MBA
Good to know. I had already (before I found the suggestion to delete the files) changed the password to basically everything I could into first: App store, iTunes store, Facetime, Messages, etc. I had likely done most of what you were required to do after deleting the files.
For anyone still running into this issue, try changing every password you can by launching individual apps, then try removing those files and attempting to hit the iCloud control panel again.
Good luck!
I solved it by disabling two-factor-authentication through http://appleid.apple.com/.
I'll try enabling it again when El Capitan hits Gold Master.
Good luck!
I had the same problem for like a month. I reinstalled, rebooted, removed some pref-files. Nothing helped. I even encountered the problem in the GM.
Other accounts were able to log in so I finally tried to turn off two-steps-verification (which I had enabled and the other account did not).
This helped for me.