Dear Ajay,
I'm shocked too !
there is no default profit center assigned to the G/l account, the really weird thing is in the GR document there is another line with another material which also does not have a profit center in it.
PUT it got posted with no problem, and in the GR document in this material line i found a profit center 1100 which is really weird !!!
is taking off the mandatory check box to post the document applicable or might make another issue
Regards,
Ahmed Samir