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

# Invalid Property Error

<Warning> **Deprecated:** This event is deprecated and will continue to be supported for backward compatibility. We recommend using the [Personalization Response Error](./personalization_response_error) instead. </Warning>

An event triggered when the web store receives malformed or invalid data in the session or offer configuration, typically due to incorrect formatting or missing required fields.

**Event Data**

<ResponseField name="eventName" type="string">
  Event name: `webstore.personalization_api.error.invalid_property`.
</ResponseField>

<ResponseField name="eventId" type="string">
  Event ID. Use this ID to deduplicate re-delivered events.
</ResponseField>

<ResponseField name="timestamp" type="number">
  Event timestamp in [Epoch time](https://www.epoch101.com/), represented in milliseconds. Example: `1754307361396`.
</ResponseField>

<ResponseField name="sessionId" type="string">
  The [session ID](/../../api-reference/events/v2/introduction#session-id) of the player’s current session. Example: `345397c6-d963-4aa4-a0ba-2aaca6c3ee05`.
</ResponseField>

<ResponseField name="requestId" type="string">
  ID assigned by Appcharge to each request sent to the publisher. Helps the publisher identify and debug failed requests.
</ResponseField>

<ResponseField name="result" type="string">
  Event result. This field is not currently in use.
</ResponseField>

<ResponseField name="reason" type="string">
  Reason for the invalid property error.
</ResponseField>

<ResponseField name="attributes" type="map<any,any>">
  A key-value map used to label events for tracking personas or tests. Example: `{ "persona":"non_payer", "blackFridayTest":"Base_group" }`
</ResponseField>

<ResponseField name="customer" type="object">
  Information about the player.

  <Expandable title="properties">
    <ResponseField name="id" type="string">
      Player ID.
    </ResponseField>

    <ResponseField name="name" type="string">
      **Deprecated.** Reserved for the player's name in future versions.
    </ResponseField>

    <ResponseField name="email" type="string">
      **Deprecated.** Player email address.
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="sessionMetadata" type="any">
  Session metadata for passing data to Appcharge to be returned later.
</ResponseField>

<ResponseExample>
  ```json Event Payload theme={"system"}
  {
    "eventName": "webstore.personalization_api.error.invalid_property",
    "eventId": "3f5bffbc-369e-4599-8c4d-abfe0ae0ef96",
    "timestamp": 1754307361396,
    "sessionId": "345397c6-d963-4aa4-a0ba-2aaca6c3ee05",
    "requestId": "23539478-c744-566a-c78c-c4cc7763ff62",
    "result": null,
    "reason": "Invalid property value",
    "attributes": {
      "persona": "non_payer",
      "blackFridayTest": "Base_group"
    },
    "customer": {
      "id": "671e81bb-55ef-428b-97ba-f67783971e0d",
      "name": null,
      "email": null
    },
    "sessionMetadata": { "abTest": "group1", "locale": "en-US" } 
  }
  ```
</ResponseExample>