Linkage does not work when first time fail
Please refer to the attached linkage for problem description.
InvoiceLine is portal row of invoice layout. I use the linkage between InvoiceLine and Product to check the SKU existing or not. The validation is in SKU field OnObjectValidate script.
If Inv_Invoiceline::SKU <> Inv_Product::SKU
The validation works fine on the first entry of invalid SKU. And it always exit with false when the invalid SKU is changed to valid SKU.