Access append query validation rule error

[AstroTek]

The only criteria is null or not null. I have checked the table description in the design view to match source and destination. There is no auto number in the destination table, I am importing only the one query.INSERT INTO Appendtlb ( [Bottler Nbr], bill_bp_ent_id, [BP Role ID], [Bottler Name], [Member Name], [Bottler City], [Bottler State], [Bottler Zipcode], [Size], [Product Description], [Product Quanity], [Member Address], [Member City], [Member State], [Member Zipcode], [Member Phone] )
SELECT Billingnumqry.[Bottler Nbr], Billingnumqry.bill_bp_ent_id, Billingnumqry.[BP Role ID], Billingnumqry.[Bottler Name], Billingnumqry.[Member Name], Billingnumqry.[Bottler City], Billingnumqry.[Bottler State], Billingnumqry.[Bottler Zipcode], Billingnumqry.Size, Billingnumqry.[Product Description], Billingnumqry.[Product Quanity], Billingnumqry.[Member Address], Billingnumqry.[Member City], Billingnumqry.[Member State], Billingnumqry.[Member Zipcode], Billingnumqry.[Member Phone]
FROM Billingnumqry;

 

[Sheco]

Is it possible that you are inserting a Null into a field that is marked Not Null?