Problem in Load Test

Hi, I’m evaluate GoDiagram Web v4.2
Now I use VS2008 load test and IIS 7.5 to evaluate the max user number
My scenario is begin at 1 user and add 1 user per 5 seconds, think time 5 seconds
every user are link to a page include 52 node and 51 link like this:

and the result is link this:

there are no error even user are grow to 1000, but I use browser visit the webpage (suppose user are 200), the picture is not appear like this:

I’m confusing why load test still continue to execute, and there are no error message(like 500 Internet Service Error)?
So, I can’t evaluate the max user of this webpage
Do GoDiagram disable the error message?

thank you very much!!!

We call System.Diagnostics.Trace if there is an error creating the Bitmap to write the image.

I will try how to get the error message