I'm trying to populate a combo box via a fill method of a business object.  When I click the "..." button of the PopulationDataSourceSettings property, I get the following error when SF is searching for all of the Business Objects:

ConstraintException
  Column 'value' is constrained to be unique.  Value 'BBS.Biz.Base.AuditBO' is already present.
Source     : System.Data
Stack Trace: 
   at System.Data.UniqueConstraint.CheckConstraint(DataRow row, DataRowAction action)
   at System.Data.DataTable.RaiseRowChanging(DataRowChangeEventArgs args, DataRow eRow, DataRowAction eAction, Boolean fireEvent)
   at System.Data.DataTable.SetNewRecordWorker(DataRow row, Int32 proposedRecord, DataRowAction action, Boolean isInMerge, Int32 position, Boolean fireEvent, Exception& deferredException)
   at System.Data.DataTable.InsertRow(DataRow row, Int32 proposedID, Int32 pos, Boolean fireEvent)
   at System.Data.DataRowCollection.Add(DataRow row)
   at MicroFour.StrataFrame.Extensibility.ListPopulationEditorDialog.ᜂ()
   at MicroFour.StrataFrame.Extensibility.ListPopulationEditorDialog.ᜁ(Object A_0, EventArgs A_1)

After I close the error message, the SF dialog is there, but with no Business Objects or methods to choose from.  Can someone please advise on what might be causing this error? Thanks in advance.

I am having the exact same issue. I searced through the entire project for a the duplicate BO without finding it? I know that I did not create a duplicate?

Any additional ideas?

ConstraintException
  Column 'value' is constrained to be unique.  Value 'Trax_System.aBOCustomer' is already present.

Source     : System.Data

Stack Trace:
   at System.Data.UniqueConstraint.CheckConstraint(DataRow row, DataRowAction action)
   at System.Data.DataTable.RaiseRowChanging(DataRowChangeEventArgs args, DataRow eRow, DataRowAction eAction, Boolean fireEvent)
   at System.Data.DataTable.SetNewRecordWorker(DataRow row, Int32 proposedRecord, DataRowAction action, Boolean isInMerge, Int32 position, Boolean fireEvent, Exception& deferredException)
   at System.Data.DataTable.InsertRow(DataRow row, Int32 proposedID, Int32 pos, Boolean fireEvent)
   at System.Data.DataRowCollection.Add(DataRow row)
   at MicroFour.StrataFrame.Extensibility.ListPopulationEditorDialog.ᜂ()
   at MicroFour.StrataFrame.Extensibility.ListPopulationEditorDialog.ᜁ(Object A_0, EventArgs A_1)

We actually traced and reproduced this the other day, so I know that the environment sees two BOs with the same name and namespace.  You may want to check your references, do a clean solution, etc. and go at it from that approach.  You may not have created a second instance, but your AppDomain and environment may see two references.  This can happen if you have residue out in your Bin folder (or some other folder in the path) and the reference sees a different BO instance that you are expected (i.e. a project reference).

If you use source control, make sure everything is checked in, delete your local work folder, then get everything back from source control.  Do a Clean Solution, then you may want to remove and re-add your references.  Then once you  make these changes, rebuild the solution (not just a build), get out of VS and come back in.  That is where I would start.