Validation rule error messages not showing up on multiple entry Order Product page

Question

I am working on Standard Order and Order Product objects. Here's the scenario: Restrict users from entering more than 100 Order Product items in Quantity on an Order.

I've created a Rollup summary field on Order that sums the quantity of Order Product child items. Next, I've created a Validation Rule on Order that has the simple rule: Order_Quantity__c > 100

I've activated the validation rule and it works perfectly when I edit an existing Order Product's quantity.

However, when I add multiple Order Products or "Edit All" the existing Order Products and Save, the records are not saved but there's no validation error showing up either.

Is this an existing bug ? The Salesforce page seems to be /orderitem/MultiOrderItemEdit

Answer 1

That'll be too late for the original post, but here's a solution: The Validation rule on the Order will trigger but won't show on the "Order Product" lines on the multi-line view. You've to copy you validation rule from Order to Order Product and choose to display the message on one of the Order Product field visible on the page layout. Since the Validation Rule on Order Product will be triggered before the Order ones, the message will be displayed.