Computer can no longer sign in to iCloud

As of today, my computer has suddenly stopped allowing access to my iCloud account. I can still use iCloud on all my IOS devices. My first clue was my iCloud email address was offline. Attempting to go online results in a window asking for my password, but inputting password simply reverts back to an offline account. Checking the iCloud setting under preferences shows an offline condition, and asks me to input a password, which simply loops right back to the offline setting. All the iCloud icons are greyed out and inaccessible.

I can access iCloud via all my IOS devices, as well as via the internet, but not from the computer.

Any ideas?