ModifyBOSl not working

Hi sir,
My code is as under:

ModifyBOSl("NFO","NIFTY18JANFUT", "180109001477764", "180109001477762",10625)

Where OrderID="180109001477764" and ParentOrderID="180109001477762"
But this code is throwing error: Invalid 'quantity'
There is no 'quantity' parameter in ModifyBOSl.

This code was working fine since last 6 months. But this problem has arisen suddenly in last week and is persisting now.

Can you through some light on this ?

Regards
Deepak Kamtikar