# Troubleshooting "Cannot read properties of undefined (reading 'data')" Error

The "Cannot read properties of undefined (reading 'data')" error occurs when the Point of Sale (POS) system expects to receive data from the server but instead receives an empty response.

![Cannot read properties of undefined (reading 'data')](https://wcpos.com/wp-content/uploads/2023/06/response-error.png)

## Possible Causes[​](#possible-causes "Direct link to Possible Causes")

* **Plugin or theme conflicts:** Conflicts with other WordPress plugins or themes can interfere with data retrieval and cause empty responses.
* **Outdated software versions:** Using outdated versions of WordPress, plugins, or themes can lead to compatibility issues and unexpected behaviour. Please make sure you have the [minimum requirements](/getting-started/installation.md).
* **Server misconfiguration or issues:** There might be server misconfiguration or issues, such as insufficient memory, limited execution time, or server-side errors, that prevent the proper generation and delivery of data.

## Troubleshooting Steps[​](#troubleshooting-steps "Direct link to Troubleshooting Steps")

### 1. Check the Network Tab in the Browser[​](#1-check-the-network-tab-in-the-browser "Direct link to 1. Check the Network Tab in the Browser")

1. Open the POS application in your browser.
2. Open the developer tools by right-clicking on the page and selecting "Inspect" or by pressing `Ctrl + Shift + I` (or `Cmd + Option + I` on macOS).
3. Navigate to the "Network" tab in the developer tools.
4. Look for the failed request, usually marked in red or with a relevant HTTP status code (e.g., 500 Internal Server Error).
5. Select the failed request to view its details.
6. Examine the response section of the request for any error messages or issues with the JSON data.
7. Copy any relevant error messages or take a screenshot.

### 2. Check the WooCommerce Fatal Error Logs[​](#2-check-the-woocommerce-fatal-error-logs "Direct link to 2. Check the WooCommerce Fatal Error Logs")

![Fatal Error Logs](https://woocommerce.com/wp-content/uploads/2018/11/wc_log_fatal_errors.png)

[WooCommerce Fatal Errors Log](https://woocommerce.com/document/finding-php-error-logs/) Example

1. Log in to your WordPress Admin area.
2. Navigate to "WooCommerce" > "Status" > "Logs" in the WordPress sidebar menu.
3. Locate the "fatal\_error" logs section.
4. Click on the log entry corresponding to the day when the error occurred (usually today's date) to view the details of the error.
5. Identify the cause of the error as logged in this section.

### 3. Check the POS Logs[​](#3-check-the-pos-logs "Direct link to 3. Check the POS Logs")

The POS [Logs screen](/support/logs.md) may also contain relevant error information and error codes that can help identify the issue.

## Getting Help[​](#getting-help "Direct link to Getting Help")

Share the error message with our support team:

[Discord Community](https://wcpos.com/discord)<support@wcpos.com>

Pro Users

If you are a **Pro user**, you are eligible for priority support. Our team will troubleshoot these issues for you. To upgrade to Pro and enjoy the benefits of priority support, please [visit our Pro page](https://wcpos.com/pro) for more information.