It's now easier to identify missing required fields in Create Records elements when you save a flow. Flow Builder warns you when a Create Records element that uses a record variable is missing an assignment for a required field. Previously, Flow Builder didn't indicate which required fields were missing from a Create Records element. You discovered missing fields only when the flow ran and failed.
Where: This change applies to Lightning Experience in Professional, Enterprise, Performance, Unlimited, and Developer editions.
How: The validation runs automatically when you save a flow in Flow Builder. If a Create Records element is missing a required field assignment on a record variable, Flow Builder shows a warning in the validation panel. Add the missing field assignment, then save again to clear the warning. The validation only checks assignments that it can determine at design time. If the flow populates a required field through an input variable or subflow, the validation can't determine its value until the flow runs.