Hi Raghu,
if its patches issue then you won't se s process chains on your colleague machine also who works with you in same project. as you said check at authorization wise also.
you can log with your id on colleague machine and check it. its same blank screen, then might be authorizations issue. Meanwhile seek basis help ask them is there any Changes to your user roles/authorizations.
other wise as stated by mates, GUI issue on your machine may be one reason. check in that way also.
if possible ask them basis team install the sane GUI which your colleague had on her/his machine.
Thanks