Why is a lookup or user field blank, or "User does not exist", after an integration update?

Short answer: Lookup and user fields need the system _id of the record or user. Map _id instead of the name or key, and the field fills in correctly.

Why it happens

Lookup and user fields store the system-generated _id of the record or user, not its display name or key. When you map a name, Kissflow can't match it to a record, so a lookup stays blank and a user field fails with User does not exist in account.

How to fix it

1. For a lookup to a dataset, open the Update an item action and map the record's _id, for example data[]._id, not the Name or Key column.
2. For a user field, map the user's _id, for example Approver._id, instead of Approver.Name.
3. Test the action and check the field in the updated item.

If you're updating a board item

Pass the board item's ID, not the process item's instance ID. To make the board item's ID available, store a reference to the board item in the process, then map that ID into the board Update an item action. See Kissflow Board connector.