# Troubleshooting and safe operation

Select an error to find its source location. Correct branch labels carefully: `ture` below must be `true`.

```xml
<workflow>
  <nodes>
    <condition id="check" test="true"/>
    <log id="done" message="Done"/>
  </nodes>
  <edges>
    <edge from="check" to="done" when="ture"/>
  </edges>
</workflow>
```

A calculated value cannot also declare a literal type. Remove `type` from this example.

```xml
<workflow>
  <nodes>
    <transform id="n">
      <value name="count" type="integer" expression="input.count"/>
    </transform>
  </nodes>
  <edges/>
</workflow>
```

Check execution inputs, permissions and referenced resource IDs before running. If a field is blank, confirm its expression path and the edge from its producing step. If a retry could duplicate an external change, verify the destination's request-deduplication behavior first. Canceling a workflow cannot undo work already completed by an external service.