today I want to share how to cope with error message CreatedByID cannot be null and CreatedByScreenID cannot be null, and so on. In order to get rid of
those error messages use attributes [PXDBCreatedByID], [PXDBCreatedByScreenID],
[PXDBCreatedDateTime], [PXDBLastModifiedByID], [PXDBLastModifiedByScreenID],
If somebody has a question, how I got such error message, the answer is simple. DAC generator generated those fields for me without those attributes, so only with the help of reflector I realized how to fix my issue.