iCloud Issue After El Capitan Update 10.11.2
It seems that I have found the answer to this issue. I ran the ACL permissions repair tool at the Terminal in Recovery Mode, but when I checked the ~/Library and its subfolders from the CLI, I found that many of the subfolders were owned by another user account. (How this happened is anyone's guess.) The solution here was to Get Info for the ~/Library folder, and then ensured that I had RW access to it. Then, I simply chose to Apply to Enclosed Items...