Creating a New List for Project Entities

Hello All, I am creating a new user field ( Project Entities < Defect < User field) I enter my desired lable name and they the type will be Lookup List so I can pick from my created options. Down at the bottom now under Lookup List I click New List to creat my own list after I enter the list name and fill in the field I get an Error (Exception from HRESULT: 0x800403EA) Does anyone have any ideas so I can create my own list?

Thank you,

Abear