BOM Quotation already exists

What is this Error ? When I put an entry in Sales quote I am getting this error.

The BOM Quotation already exists, Identification fields and values:

quotation id=‘1009’, document type=‘quote’, line no.=‘10000’,type=‘item’,parent item no.=‘1000’

How to solve this one.

I’m pretty sure BOM Quotation is a custom table in whatever database you are in. What have you already done to figure out what is wrong? It’s actually pretty easy to see where the problem is (usually) if you turn on the debugger.