In reply to mpattaje:
Actually the error message showed me that error the error as below:
Fatal error in Function create_object at /opt/questasim_6.6e/questasim/linux/../verilog_src/ovm-2.1.1/src/base/ovm_registry.svh line 182
But I don't know how this is related to my peice of code, else it is difficult to trace. I listed all my new & create calls and don't see I used that for a abstract class.