# Response Error A response error means your store's website answered the POS with nothing, or with something that isn't data: an error page, a PHP warning or a security check. The fault is on the website, not the till. ## At the till[​](#at-the-till "Enlace directo a At the till") Don't charge twice After **CHECKOUT201**, the customer may already have paid. Open the order and check its status before you take payment again. The steps are on the [CHECKOUT201](/es/error-codes/CHECKOUT201.md#troubleshoot) page. 1. **Check the action finished.** Look for the product or customer you were saving. If it's there, carry on. For a sale: * Find the order: with WCPOS Pro in **Orders** (refresh it first, as the CHECKOUT201 page shows); without Pro, someone opens **WooCommerce → Orders** in WP Admin. * **Processing** or **Completed**: the sale went through. Don't charge again. * Not paid, or not found: check the card provider's screen or the cash drawer. 2. **Try once more.** A one-off failure often clears on the next try. After **CHECKOUT201**, only when the order isn't paid and no payment was taken. If you can't tell, [get help](#get-help). 3. **Still failing?** Open **Store health → Logs** and press **Copy debug info** (**Share debug info** in the phone and tablet apps). [Find the error](#find-the-error) below shows where. Send it with the error code to whoever looks after your website, or to WCPOS support. Don't clear this device's data to make the error go away. It may hold changes your store doesn't have yet. See [Clear Local Data](/es/troubleshooting/clear-local-data.md). ## Find the error[​](#find-the-error "Enlace directo a Find the error") Open **Store health** and go to **Logs**. Tap **Errors** to see only the problems, then tap a row to open it. **SYNC151**, and a **SYNC131** on a change the POS is still retrying, are warnings: find them under **All**. ![Store health, Logs tab, filtered to Errors, with one error row opened: what the store said, what to do, the Help link for the error code, the Copy button for the entry, and Copy debug info at the top](/img/2.x/support/troubleshooting/response-error/en/tablet-light-regular--re-1-logs-error-row.png)1234567 1. **Store health** — the heartbeat icon in the side bar. A red badge counts errors you haven't read. On a phone, it's in the menu at the top left. 2. **Logs** — everything this device did and every problem it met, kept for up to 30 days. See [Logs](/es/troubleshooting/logs.md). 3. **Errors** — shows only the rows that need attention. The code at the end of each row names the problem. 4. **The opened row** — what the store said, what to do next, and under **Request** the status the store answered with. This example is a refused change (`403`). A response error ends in **SYNC131**, **SYNC151** or **CHECKOUT201**, often with a `500`. 5. **Help** — opens the page for that error code. 6. **Copy** — copies this one entry, to paste into a message to support. 7. **Copy debug info** — copies a report of this device and its recent errors. In the phone and tablet apps it reads **Share debug info**. ## What the codes mean[​](#codes "Enlace directo a What the codes mean") Older versions of WCPOS showed a response error as `Cannot read properties of undefined (reading 'data')`. Now the row in Logs ends with one of these codes: * **[SYNC131](/es/error-codes/SYNC131.md): Your store had an error and didn't finish this request.** The website failed while handling the request, or sent back a page instead of data. * **[SYNC151](/es/error-codes/SYNC151.md): Your store's reply had stray text in it, which WCPOS tried to clean up.** A plugin or theme printed text, often a PHP warning, in front of the data. The POS removed it; check the action finished. * **[CHECKOUT201](/es/error-codes/CHECKOUT201.md): WCPOS could not confirm whether checkout completed.** The sale was sent, but no answer came back. The order may exist and may be paid. * **[HOST121](/es/error-codes/HOST121.md): A bot-protection page is answering instead of the store's API.** A firewall or security service answered for your store. The POS checks for this when you connect the store; later, the same page shows as SYNC131. See [Cloudflare](/es/troubleshooting/common-problems/cloudflare.md). A red bar that reads **Something went wrong:** followed by technical text is a different problem: part of the screen failed to draw. Close it with the **X**. See [CLIENT151](/es/error-codes/CLIENT151.md). ## Get help[​](#get-help "Enlace directo a Get help") Send the error code and the debug info to WCPOS support on [Discord](https://wcpos.com/discord) or at : [Discord Community](https://wcpos.com/discord) With WCPOS Pro Pro includes priority support in the Pro channels on Discord. Connect your Discord account to your licence to open them: see [Where to ask](/es/troubleshooting/contact-support.md#where-to-ask). ## Find the cause on the website[​](#find-the-cause "Enlace directo a Find the cause on the website") These steps are for whoever looks after your WordPress site. For the site admin: the error log, the reply and what it tells you ### Read the store's error log[​](#error-log "Enlace directo a Read the store's error log") 1. In WP Admin, go to **WooCommerce → Status → Logs**. 2. Open the newest `fatal-errors` log from around the time of the error. A PHP crash leaves a line there naming the plugin or file. The POS plugin's own log, **POS → Settings → Logs**, shows **Fatal errors detected — view in WooCommerce logs** when there are any. See [Critical Error](/es/troubleshooting/common-problems/critical-error.md). ### Read the reply itself[​](#read-the-reply "Enlace directo a Read the reply itself") 1. Open the POS in a desktop browser at `yourdomain.com/pos`. In the desktop app, use **Advanced → Toggle Developer Tools** instead. 2. Open the developer tools: right-click the page and choose **Inspect**, or press `Ctrl + Shift + I` (`Cmd + Option + I` on a Mac). 3. Go to the **Network** tab and repeat the action that failed. Never repeat a payment whose result you don't know: check the order first, as in [Don't charge twice](#at-the-till). 4. Click the failed request, shown in red or with a `5xx` status, and read its **Response**. ### What the reply tells you[​](#what-the-reply-tells-you "Enlace directo a What the reply tells you") * **`Warning:`, `Notice:` or `Deprecated:` text before the `{`.** A plugin or theme is printing PHP messages into every reply. Turn off on-screen PHP messages (`WP_DEBUG_DISPLAY` set to `false`), then fix or replace the plugin. See [Plugin Conflicts](/es/troubleshooting/common-problems/plugin-conflicts.md). * **"There has been a critical error on this website".** PHP crashed. Read the fatal-errors log above. See [Critical Error](/es/troubleshooting/common-problems/critical-error.md). * **A security check or "verify you are human" page.** A firewall or bot protection is answering for the store. Allow the store's REST API through. See [Cloudflare](/es/troubleshooting/common-problems/cloudflare.md). * **Nothing at all, with a `500`, `502`, `503` or `504` status.** The server ran out of memory or time. Ask your host for the PHP error log and your limits. See [Server Performance](/es/troubleshooting/performance/slow-server.md#503-errors). * **None of these, or it started after an update.** Check that WordPress, WooCommerce and PHP meet the [minimum requirements](/es/getting-started/installation.md#server-requirements). Still stuck? Send what you found in the reply, with the error code, to WCPOS support ([Get help](#get-help)). ## Related Documentation[​](#related-documentation "Enlace directo a Related Documentation") [Critical ErrorFind the PHP error behind a crashed store](/es/troubleshooting/common-problems/critical-error.md) [Plugin ConflictsFind the plugin that breaks the POS](/es/troubleshooting/common-problems/plugin-conflicts.md) [LogsEverything the POS records on this device](/es/troubleshooting/logs.md)