Large Number of Faulted Virtual Users

We have a major concern regarding the result of our load test using test studio. Why is it that we're getting huge number of Faulted users in the Analysis Screen (page with metric graphs) even though there are no HTTP Errors (refer to - Analysis Screen.png) reported after the load test execution. Looking at the page specific metrics, all the URL pages did not encounter any error (refer to - No Errors on Page Specific Metrics.png). Also, there are no completed users for the entire life of the test.

Here's what we're aiming to achieve on the application using load test.
1. The application has a page which we call the operator console, under the operator console are lists of tasks that we need to change the status (e.g. change status from In Progress to Initiated).
*Note: There are preceeding pages that the user needs to go first before the Operator Console page.
2. So we designed our webtest to select random page on the operator console. And then, change the status of the tasks loaded on that page by selecting all the task and changing their status. (refer to - Operator Console Page.png)

We are load testing the application to see if it can handle multiple concurrent users changing the task status under the operator. However after the execution there are no completed users, meaning none of the virtuals users completed their requests and there is a huge number of faulted virtual users. Why are we getting this behavior? Also upon checking the tasks on the operator console page manually, NONE of the tasks changed status.

BTW, we are using Windows Authentication for our application.

Thanks. Hope you could help us ASAP with this.

Thanks,
Cairo