I’m trying to create a bill of materials (BOM) table, the BOM links to the part number by the part number, The main form is named ‘New Part’ and the part number to assign the child material is held on the main form in a text box called ‘SCS Part Number’
The child materials are assigned in a subform named ‘Qry_BOM_RequirmentsV1 subform’ each new record is assigned the part number. This is achieved by using the after-update event property. When the material is selected from a combo box the part number from the main form is assigned to the ‘PrtNmber_LinkField’

Private Sub RequiredMaterialPrtNum_AfterUpdate()
[PrtNmber_LinkField] = Me.[SCS_Part_Number]
End Sub
Its assigning the part number into the correct field but returning an error

Any ideas what’s causing it?