Unable to draft an email in icloud.com

when i am in icloud.com, i click on the draft icon. the new window is slow to open up. once it does, i attempt to click on the To: field to put in an address. the cursor disappears, then reappers, yet i am unable to type. it is also very slow, i click on the body of the email, but i takes a while for the cursor to appear. i am able to type text in the body of the email, but can not in the email address fields.

we have had this computer for about 1yr, and this is the first time this has happened. other websites are running as normal.