vSphere Web Client HTML: getting exception while calling WEB_PLATFORM.sendModelChangeEvent

Hi,

I have a view in my HTML plugin that shows a list of objects on the LHS and a more detailed list with multiple columns in the center. I have an action in the menu for an object which is in LHS, that opens a dialog which allows the user to enter some information and to perform the action. When the user clicks on "submit" a request is made to my service-layer and an object is created in the back-end. Now I want my lists to update accordingly. Here's my problem:

At first, I used WEB_PLATFORM.callActionsController(URL,json) to make the call to the service layer. The two lists are getting updated nicely and everything works fine. However, 2nd-time if try to perform same action on same object WEB_PLATFORM.callActionsController(URL,json) throws exception.

here
taskStatusUrl = webContextPath + serviceAPI + {parameter} + '?actionUid=' + actionUid
jsonData = {actionText: actiontext, operationType: operationType, objectType: objectType}

This issue is happening only if the 1st task is still not complete, And try to perform 2nd-time same action on the same object.

Thanks for your help!