sign in/ unknown error occurred/ can't sign into iCloud
Hi,
I've been getting messages on both my MacBook pro (OSX 10.13.6) and iMac (OSX 10.11.6) constantly stating 'can not connect to iCloud' then I have to re-enter my iCloud password in system preferences where it either accepts my password or gives me 'Unknown error occurred' message (please see pictures below).
I grew tired of re-entering my password on my MacBook and decided to try signing out and signing back into iCloud, but now it won't let me sign in. It neither declines or errors, just acts as thought no id and password was entered and goes back to sign in window.
I can sign in without problem on iCloud.com and both devices are registered on
Please help me, what do I do???