UVM Agent connect phase error connecting driver to sequencer

In reply to cgales:

Dear cgales,
thanks for your kind reply. First thing is Line 47 is the line below in code posted above.
i2c_drvr.seq_item_port.connect(i2c_sqr.seq_item_export);

Secondly you are perfectly right! I also figured this out that my configuration object is NULL. But the problem is that even though i am making my configuration object as like uvm_active_passive_enum is_active;
Then I registered it with uvm_field_enum
and then i have put a constraint like this:
constraint i2c_master_configuration::is_active_agent_c{soft is_active==UVM_ACTIVE;}

But it is not making it active anyway!!

Any idea? what is wrong?