This should be updated to 1500 seconds because Facebooks servers sometimes process messages out of order when using images due to the file size processing time. 1500 seconds seems to fix it.

Author: tkornblit

lib/CoreBot.js

@@ -823,7 +823,7 @@ function Botkit(configuration) {
             // set up a once a second tick to process messages
             botkit.tickInterval = setInterval(function() {
                 botkit.tick();
-            }, 1000);
+            }, 1500);
         }
     };