title: How to solve a sudden ssl_cacert error of Slack app that has been running flawlessly?
body: <p>I've had a Slack app up and running for quite some time which has been working flawlessly. The app sends messages that have an interactive button on it. It also has slash command interactivity.
  However, since this morning, whenever a user presses the button on the message, Slack displays an exclamation point (!) next to it with the message &quot;Error in establishing a secure connection. Please use a secure certificate for the interactivity URL of this app.&quot;</p>
  <p>The SSL cert on my server is not expired and I've made absolutely no changes to the Request URL within the app's settings. Does anyone know what the problem may be?</p>