i began to get this strange error:

ER onItemUpdate exception
this.LS_QfY.LS_WPo is undefined

Where this seems to be property from my schema, but i do not have such in it(i can see what are the schema properties from the ls console).
I am getting the exception from here :
var msg = itemUpdate.getNewValue(schema[i]);
It seems that schema[i] is undefined, but why?
I noticed that this only happens when i change my schema and call restart :
private native void restart(JavaScriptObject nvt, NonVisualGWTClient thiz, JavaScriptObject page, JavaScriptObject map, String [] schema) /*-{
																															this.@com.trinitas.ls.client.NonVisualGWTClient::nvt.onItemUpdate = function(item, itemUpdate, itemName) {
																																	for (i=0;i<=schema.length;i++) {
																																				var msg = itemUpdate.getNewValue(schema[i]);
																																				if (msg !=null) {
																																					thiz.@com.trinitas.ls.client.NonVisualGWTClient::onMessage(Ljava/lang/String;Ljava/lang/String;)(msg, schema[i]);
But right before i call restart i printed the schema and it is exactly as it should be. So where does this LS_QfY.LS_WPo come from?

And one other thing: before now i used the following:

var msg=itemUpdate.getNewValue(schema[i]);																																			if(msg!=null){																																					    onMessage(Ljava/lang/String;Ljava/lang/String;)(msg, schema[i]);
Now i removed this if (msg != null) and i began to receive null messages, but i never send null message. Why is that?Why ls sends null Strings?