xPC Target Error during Simulations

I have a simulink model of a hydraulically actuated mechanical arm. It simulates just fine without any errors. However, when I upload and run it in xPC target, it immediately gives an error like "error originates in mechanical block ....." This error appears in the xPC target window while I'm running it through "External" interface of the model from host.

My question is, how can I know the details of the error. Is there a file on xPC target where all errors are recorded in a bit detail?

[Syed]

Anyone?