Merged in paulis/processmaker/PM-1939 (pull request #1767)

I solved the issue PM-1939 PM-1940

workflow/engine/js/processmap/core/processmap.js

@@ -2232,7 +2232,10 @@ var processmap=function(){
     /*
     * Aca se definen  TASK inicio y TASK a la que se deriva.
     */
-    event = event || window.event;
+    //In IE the event is undefined or 0
+    if(event === 0 || typeof(event) === 'undefined'){
+      event = window.event;
+    }
 
     if (event)
     {