Upgrade by March 4, 2020 — TL;DR On March 4, 2020, Slack will end support for Transport Layer Security (TLS) versions 1.0 and 1.1. In advance of this, we will implement a 24-hour test deprecation on February 19, 2020. If your Slack app or organization is using an unsupported version of TLS, requests sent to any Slack…