> ## Documentation Index
> Fetch the complete documentation index at: https://developers.redo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CheckoutTreeDiagnostic

> A problem in a checkout tree.

**Required scopes:** [`checkout_read`](https://developers.redo.com/docs/api-reference/v3/reference/scopes#scope-checkout_read)

**blocks** `[CheckoutTreeDiagnosticBlocks!](/docs/api-reference/v3/reference/checkout/checkout-tree-diagnostic-blocks)` *required*

What it stops.

**code** `String!` *required*

A stable code, such as CT0105. Read `diagnostics/<code>` in `checkoutTreeCatalog`.

**message** `String!` *required*

What is wrong.

**stepId** `String`

The step it is on; null for the tree as a whole.


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