diff --git a/docs/customization.md b/docs/customization.md
index 9c9d78f..476ef84 100644
--- a/docs/customization.md
+++ b/docs/customization.md
@@ -11,16 +11,17 @@ We assume that you are already familiar with setting up bpmn-server along with y
 
 Please note code in this page is for illustration purposes only.
 
-
 ## Workflow Application Components
 
 ### UI and User Authentication
 
 In the demo app:
+
 - root files
 - Web Files; views, routes, public
 
 ![](images/bpmn-web-folders.png)
+
 ### Workflow app
 
 <table>
@@ -46,15 +47,13 @@ Entry point to application configuration parameters and defining various compone
 This is your custom installation of bpmn-server 
 
 
-# Putting it Togother
-
-## Use Case 1: Staging a Process
+### Use Case 1: Staging a Process
 In this use case a User invokes some business logic that requires a process start ...
 When a process reaches a User Task it issues a notification to user(s).
 
 ![](images/processStart.png)
 
-## Use Case 2: Invoking an Oustatnding Tasks
+### Use Case 2: Invoking Oustatnding (User Tasks in wait state) Tasks
 
 
 ![](images/invokeTask.png)
diff --git a/src/elements/Definition.ts b/src/elements/Definition.ts
index 8a88d45..a56aa6a 100644
--- a/src/elements/Definition.ts
+++ b/src/elements/Definition.ts
@@ -117,10 +117,13 @@ class Definition implements IDefinition{
 
         processElement.laneSets.forEach(ls=>{
             ls.lanes.forEach(lane=>{
-                lane.flowNodeRef.forEach(fnr=>{
+                if (lane.flowNodeRef) {
+                    lane.flowNodeRef.forEach(fnr=>{
                         let target = this.getNodeById(fnr.id);
                         target.lane=lane.name;
                     });
+                }
+
                 });
             });
         }