cause tirefires

docs/administration-guide/08-setting-up-slack.md

@@ -21,7 +21,11 @@ Click over to the tab that was opened and you'll now be on the Slack Bot creatio
 
 Now give the Bot user a helpful name (we suggest `Metabot`) and click the `Add bot integration` button and a bot user will be generated for you.  Look for the Bot's API token in the next page. It will look like `xoxp-etc-etc-etc` and all you need to do is copy that value and head back to Metabase.
 
-Paste the value into the text box for `Slack API Token` and click the button to save your changes.  That's it!  Metabase will automatically run a quick test to check that the API token is working properly and if not you'll get an error message.
+Paste the value into the text box for `Slack API Token` and click the button to save your changes.  
+
+Now go to slack and create a new channel named `metabase_files`. Due to the slack api, we need this to attach graphs to pulses and Metabot answers.
+
+That's it!  Metabase will automatically run a quick test to check that the API token is working properly and if not you'll get an error message.
 
 ---
 

frontend/src/metabase/admin/settings/components/SettingsSlackForm.jsx

@@ -211,7 +211,7 @@ export default class SettingsSlackForm extends Component {
                         </a>
                     </div>
                     <div className="py2">
-                        Once you're there, give it a name and click <strong>"Add bot integration"</strong>. Then copy and paste the Bot API Token into the field below.
+                        Once you're there, give it a name and click <strong>"Add bot integration"</strong>. Then copy and paste the Bot API Token into the field below. Once you are done, create a "metabase_files" channel in slack. Metabase needs this to upload graphs.
 
                     </div>
                 </div>