> For the complete documentation index, see [llms.txt](https://developers.oxylabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.oxylabs.io/products/agent-browser/troubleshooting-guide.md).

# Troubleshooting Guide

Learn how to handle unexpected behavior or low success rates when using Oxylabs Agent Browser.

| Symptom                                                       | Likely cause                                         | Solution                                                                                                                         |
| ------------------------------------------------------------- | ---------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| *Session inspection (VNC) unable to connect (browser starts)* | Max VNC limit reached                                | Use fewer VNC sessions.                                                                                                          |
| *TLS / certificate error*                                     | Certificate validation in Node.js                    | Set `NODE_TLS_REJECT_UNAUTHORIZED="0"` before requiring Playwright (testing only).                                               |
| *Profile restored but cookies are empty*                      | Exit IP changed between sessions                     | Pin `proxy_resi_ses_id` + `proxy_resi_ses_time` with identical values every session.                                             |
| *Login wall / low success rate*                               | IP reputation, wrong geolocation, or engine mismatch | Set `p_cc`, try a different `p_device`, or switch the engine and fingerprint. Enable `page_handler=true` if a challenge appears. |
| *Target blocked entirely*                                     | Restricted target category                           | Complete KYC via your Dedicated Account Manager.                                                                                 |

{% hint style="info" %}
For connection, session, and in-page error codes, see [Response Codes](/products/agent-browser/response-codes.md).\
Still stuck? Contact Oxylabs support via live chat or email (<support@oxylabs.io>).
{% endhint %}

If you're experiencing unexpected behaviour or low success rates, consider the following steps:

{% hint style="info" %}
For connection, session, and in-page error codes, see Response Codes.
{% endhint %}

### **Understand our CAPTCHA handling process**

Familiarize yourself with our [CAPTCHA handling](/products/agent-browser/captcha-handling.md) methods and its usage. This can provide insight into whether CAPTCHA challenges are the source of the issue.

### **Use the country parameter**

Specifying a country parameter in your requests can significantly increase success rates. This ensures your requests are routed through IPs from a specific geographic location, filtering out IPs from random or potentially less reliable locations.

You can specify a country for your browser session by adding the `?p_cc` parameter to your connection URL. More information can be found in section [Geolocation targeting](/products/agent-browser/geolocation-and-proxy-selection.md).

### **Use the device type parameter**

Experimenting with a device parameter can result in higher success rates. You can customize how the browser emulates different device types by using the `?p_device` parameter. More information can be found in [Device Type](/products/agent-browser/device-type.md) section.

#### **Try different engine and fingerprint combinations**

Anti-bot protections vary by target. If you get blocked, switch between Windows and macOS fingerprints, or between the standard and proprietary browser engine. For protected targets, try `p_src=oxybrowser` with `p_fp_tag=oxyfp_mac_optimized`. More information in [Engine & Fingerprints](/products/agent-browser/engine-and-fingerprints.md).

{% hint style="info" %}
If issues persist after trying these steps, please contact your Dedicated Account Manager with details of the problem and the steps you've already taken.
{% endhint %}

## Need a feature enabled? <a href="#need-a-feature-enabled" id="need-a-feature-enabled"></a>

Some Agent Browser features are limited by default. To adjust your limits, contact Oxylabs support ([live chat](https://oxylabs.io/) or [email](mailto:support@oxylabs.io)) or your Dedicated Account Manager:

* **More persistent profiles** – raise your account's default cap of 5 saved profiles.
* **More persistent sessions** – raise your account's default cap of 5 concurrent persistent sessions.
* **Restricted targets** – unlock more target categories via KYC process.
* **Higher rate limits** – increase beyond 100 concurrent sessions / 10 per second.


---

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