What causes "error in marshaling resource changes: %s" in hashicorp/terraform?

Read the inner error to find the offending resource address and specific cause.

error in marshaling resource changes: %s

Error message

error in marshaling resource changes: %s

What it means

Top-level wrapper: serializing the primary resource_changes list via MarshalResourceChanges(p.Changes.Resources, ...) failed. The inner error usually comes from marshalResourceChange and surfaces as 615 (no schema), 616 (unsupported mode), 617 (unsupported action reason), or a decode/ctyjson error.

Source

Thrown at internal/command/jsonplan/plan.go:305

					driftedResources = append(driftedResources, dr)
				}
			}
		}
		output.ResourceDrift, err = MarshalResourceChanges(driftedResources, schemas)
		if err != nil {
			return nil, fmt.Errorf("error in marshaling resource drift: %s", err)
		}
	}

	if err := output.marshalRelevantAttrs(p); err != nil {
		return nil, fmt.Errorf("error marshaling relevant attributes for external changes: %s", err)
	}

	// output.ResourceChanges
	if p.Changes != nil {
		output.ResourceChanges, err = MarshalResourceChanges(p.Changes.Resources, schemas)
		if err != nil {
			return nil, fmt.Errorf("error in marshaling resource changes: %s", err)
		}
	}

	if p.DeferredResources != nil {
		output.DeferredChanges, err = MarshalDeferredResourceChanges(p.DeferredResources, schemas)
		if err != nil {
			return nil, fmt.Errorf("error in marshaling deferred resource changes: %s", err)
		}
	}

	if p.DeferredActionInvocations != nil {
		output.DeferredActionInvocations, err = MarshalDeferredActionInvocations(p.DeferredActionInvocations, schemas)
		if err != nil {
			return nil, fmt.Errorf("error in marshaling deferred action invocations: %s", err)
		}
	}

	// output.OutputChanges

View on GitHub (pinned to c9def3e214)

Solutions

Read the inner error to find the offending resource address and specific cause.
Run `terraform init` to install/pin the correct provider versions.
Regenerate the plan with a Terraform version consistent with the state.

Defensive patterns

Strategy: try-catch

Try / catch

changes, err := jsonplan.MarshalResourceChanges(plan.Changes.Resources, schemas)
if err != nil {
    // the inner error names the offending resource; surface it to the user
    return fmt.Errorf("marshal resource changes: %w", err)
}

Prevention

Install and pin all providers with `terraform init` before rendering.
Match provider versions between plan creation and rendering.
Treat a 'no schema found' inner error as a missing/mismatched provider.

When it happens

Trigger: Reached on every full Marshal call when p.Changes != nil. Any planned resource change that fails to marshal aborts the whole render and is wrapped here.

Common situations: Missing provider schema for a planned resource; provider version mismatch; a resource mode/action reason from a newer Terraform; corrupted plan or state.

Related errors

AI-assisted analysis of hashicorp/terraform@c9def3e214 (2026-08-07). Data as JSON: /api/errors/d71ca8eb8af061c4. Report an issue: GitHub.