Idw file losed reference idw.Where it event i can find

[Anonymous]

I have 1.idw and it reference 1.ipt. After I replace 1.ipt on 2.ipt( 2 .ipt have diferent configuration). When I open 1.idw - see Message : "Previous file 1.ipt different component from selected file 1.ipt .Component substitution is not permitted in drawing." How trace this event ? (maybe in OnOpenDocument events). Where verify difference between the 1.ipt and the 2.ipt?
Thank you for your help.

[Anonymous]

My addition and explanation:
what object of API Inventor verify difference between the 1.ipt and the 2.ipt for 1.idw ( with Reference on 1.ipt).