On 27-07-2021 starting with 07:00 EEST ( 21:00 PDT/PST ) for 4 hours, we'll be updating WordPress to the latest version 5.8 on all production instances. During this time, the wp-admin can become inaccessible for a few minutes while the new version is applied. The public sites will not be affected and they will work normally. For any inquiries during this time don't hesitate to contact us at firstname.lastname@example.org
We recommend you to test this new version on your development instance, as they have already been upgraded to the latest WP version. If you find any problems before the maintenance, please drop us an email at email@example.com
containing the Subject: "WP 5.8 upgrade problems"
More details about the new version can be found at: https://wordpress.org/news/2021/07/tatum/