I ran into the same problem. I had to delete the com.ptc.windchill.esi.txn.ESITransactionObjectLink object before I could remove the part. I don't know if the user interface provides a method to do this manually or not, I have been using info engine.Regards,
Glen Herman
Sr Application Developer
Engineering And Technology
Trane Residential Systems
6200 Troup Hwy
Tyler, Texas, 75701