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

# Fix Type Name Errors

> Resolve Nextedy POWERSHEET data model errors caused by invalid entity type names, including spaces, special characters, and mismatched references between the data model and Siemens Polarion ALM work item types.

export const LastReviewed = ({date}) => {
  if (!date) return null;
  const formatted = new Date(`${date}T00:00:00Z`).toLocaleDateString("en-US", {
    year: "numeric",
    month: "long",
    day: "numeric",
    timeZone: "UTC"
  });
  return <p className="mt-10 text-sm text-gray-400 dark:text-zinc-500 not-prose">
      Last reviewed on {formatted}
    </p>;
};

## Identify the Error

Type name errors occur when the data model contains entity type names that violate naming rules. Symptoms include:

* Connection status shows **Failed** after saving the data model
* Error messages referencing unrecognized type names
* Sheet configuration `from` field fails to match any entity type

<Steps>
  <Step title="Check Entity Type Naming Rules">
    Entity type names in `domainModelTypes` must follow strict rules:

    | Rule                   | Valid               | Invalid                  |
    | ---------------------- | ------------------- | ------------------------ |
    | Single word, no spaces | `SystemRequirement` | `System Requirement`     |
    | No special characters  | `UserNeed`          | `User-Need`, `User_Need` |
    | PascalCase recommended | `DesignRequirement` | `designrequirement`      |
    | Must be unique         | One `Hazard` entry  | Two `Hazard` entries     |

    ```yaml theme={null}
    # CORRECT - single word PascalCase names
    domainModelTypes:
      UserNeed:
        polarionType: requirement
      SystemRequirement:
        polarionType: systemRequirement
      DesignRequirement:
        polarionType: designRequirement
    ```

    ```yaml theme={null}
    # INCORRECT - spaces and special characters
    domainModelTypes:
      User Need:              # Space in name
        polarionType: requirement
      System-Requirement:     # Hyphen in name
        polarionType: systemRequirement
    ```

    <Warning title="Type names must be single words">
      Data model entity type names must be single words without spaces or special characters. This is a strict validation rule -- names with spaces will cause the connection to fail silently without a clear error message.
    </Warning>
  </Step>

  <Step title="Distinguish Entity Type Names from Polarion Type IDs">
    A common mistake is confusing data model entity type names (the YAML keys under `domainModelTypes`) with Polarion work item type IDs (the `polarionType` value):

    <Frame>
      <img src="https://mintcdn.com/none-17b4493f/-WiVljKlDztH36bB/powersheet/diagrams/guides/troubleshooting/fix-type-name-errors/diagram-1.svg?fit=max&auto=format&n=-WiVljKlDztH36bB&q=85&s=5c7e97e787a4503bc7fac20375827799" alt="diagram" style={{ width: "520px", maxWidth: "100%" }} width="520" height="120" data-path="powersheet/diagrams/guides/troubleshooting/fix-type-name-errors/diagram-1.svg" />
    </Frame>

    The `polarionType` maps your data model entity to a Polarion work item type, but all references within the data model (relationships, queries, sources) use the **entity type name** (the YAML key).
  </Step>

  <Step title="Fix Relationship References">
    When relationship `from` and `to` fields reference an invalid entity type name, you may see "left error" or "right error" messages:

    * **"left error"** = the `from` entity type name is invalid
    * **"right error"** = the `to` entity type name is invalid

    ```yaml theme={null}
    relationships:
      - from: UserNeed              # Must match a domainModelTypes key
        to: SystemRequirement       # Must match a domainModelTypes key
        cardinality: one-to-many
        storage: linkedWorkItems
        linkRole: has_parent
    ```

    <Tip title="Match YAML keys exactly">
      The `from` and `to` values must exactly match the keys under `domainModelTypes` -- including capitalization. `systemRequirement` (lowercase s) will not match `SystemRequirement` (uppercase S).
    </Tip>
  </Step>

  <Step title="Fix Source Query References">
    The `from` field in your sheet configuration sources must also use the entity type name:

    ```yaml theme={null}
    sources:
      - model: my-model
        from: UserNeed    # Entity type name, NOT "requirement" (Polarion type ID)
        expand:
          - systemRequirements.systemRequirement
    ```
  </Step>

  <Step title="Fix a Wrong-Case `polarionType` Value">
    This is the single most common reason for an empty sheet, and it produces **no error message at all**.

    * **Symptom:** The sheet opens but is completely empty -- no rows load, the connection status looks fine, and no error is shown.
    * **Cause:** The `polarionType` value does not match the Polarion work item type ID exactly, usually because of wrong casing. For example, using `systemRequirement` (camelCase) when the actual Polarion type ID is `sys_req`. Polarion type IDs are case-sensitive, so a near-miss silently matches zero work items.
    * **Fix:** Check the exact work item type ID in your Polarion project (Administration > Work Items > Types) and use that exact string -- including case and underscores -- as the `polarionType` value.

    ```yaml theme={null}
    domainModelTypes:
      SystemRequirement:
        polarionType: sys_req          # CORRECT - exact Polarion type ID
        # polarionType: systemRequirement  # WRONG - silent empty sheet
    ```
  </Step>
</Steps>

## Verification

After correcting type names:

1. Save the data model configuration
2. Check that the connection status returns to **Active**
3. Open the powersheet document
4. You should now see data loading correctly with no type-related errors in the sheet

## See Also

* [Create an Entity Type](/powersheet/guides/data-model/create-entity-type) -- entity type setup guide
* [Fix Model Connection Errors](/powersheet/guides/troubleshooting/fix-model-connection-errors) -- diagnose data model connection failures
* [Fix Relationship Errors](/powersheet/guides/troubleshooting/fix-relationship-errors) -- relationship configuration issues
* [Validate Your Data Model](/powersheet/guides/data-model/validate-model) -- full validation checklist

***

<LastReviewed date="2026-07-02" />