@sarankon-hir The OpenIG log file can give more informatio on why this is happening.
From what I guess, this might be a configuration error in OpenAM. When I did the screen-cast for this activity, I ran into similar issues and all of them were configuration errors in OpenAM (specifically spelling mistakes in the OpenAM Configuration parameters, or Post Authentication Plugin name etc.). Could you please double check.
I can confirm that the steps in documentation works as expected.