iCloud has stopped responding

Trying to log in to iCloud on my iMac running iOS 10.13.6. As soon as I start to type in my username, I am given a message saying iCloud has stopped responding. I still appear to be able to get access to photos on my phone, but can't log in on the computer. I have restarted the computer but still get the same result. I have also cleared the browsing history. The details are shown below. They don't mean anything to me, but someone may make sense of them.

APP NAME

cloudos2

CLIENT TIME

Sat May 02 2020 13:27:21 GMT+0100 (BST) (1588422441276)

USER AGENT

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1 Safari/605.1.15

HOSTNAME

www.icloud.com

BUILD INFO

2007Project56__2007B28__en-gb

SESSION ID

a4372fb2-58dd-4070-bb4e-4723f03d885f

ENVIRONMENT INFO

PROD

REPORTED ERROR TITLE

undefined is not an object (evaluating 'e.authorization.method=e.event')

REPORTED ERROR TYPE

UNHANDLED_EXCEPTION

ERROR CONTEXT

undefined

LINE NUMBER

11

STACK

decode@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:1356470

https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:826943

_actuallyInvokeObserverCallback@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:102253

calculateValueForNode@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:101718

le@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:92376

ce@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:92060

setValueForNode@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:94683

https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:107034

p@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:828784

p@[native code]

r@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:439701

a@https://www.icloud.com/system/cloudos2/2007Project56/en-gb/main.js:11:468390