troubleshooting

Scrapy's TunnelError means the proxy answered the CONNECT request with a status other than 200. What each status means, the Proxy-Authorization trap, and the fix.

YouTube shows this when the address or session looks automated. What it means in a browser and in yt-dlp, the wiki's cookie advice, and where a proxy helps.

SOCKS5 replies are numbered by the protocol, so each error names its cause. What the reply codes and authentication failures mean, and the fix for each.

Cloudflare's block page means a site's rule refused your request, usually because of the address you came from. What triggers it and what you can change.

Spotify shows error code 4 when the desktop app cannot reach its servers and blames the firewall or the proxy settings. Which proxy mode to pick, and what else breaks it.

Chrome and Edge show this when Windows points at a proxy that does not answer, and most people never set one. How to find it, switch it off, and stop it returning.

Chrome's older wording for ERR_PROXY_CONNECTION_FAILED, still common on Android and Chromebooks. Where the proxy setting lives on each device and how to clear it.

What the troubleshooter actually checked, why it blames the proxy, and the fixes in order: a leftover proxy setting, WinHTTP, the VPN, Winsock, and the driver.

407, 403, 429, 502, 504, ERR_PROXY_CONNECTION_FAILED, cURL 7 and 56. One triage method sorts all of them by which leg failed, which is the only thing that picks the fix.

WebSockets fail through proxies in three specific ways, and provider docs almost never mention it. The two-minute test, how to read the failure, and why rotation is the usual culprit.

Akamai's _abck cookie carries a trust state, not a session id. Learn to read it, understand the three sensor posts that flip it, and tell apart the four ways a session still fails after it goes valid.

AWS WAF Bot Control scores your IP reputation, your TLS (JA3) fingerprint, a JavaScript token that interrogates your browser, and your session behavior. Residential proxies fix the reputation part. The other three signals you bring yourself.

Fastly's Next-Gen WAF, formerly Signal Sciences, scores your IP and NLX reputation, your request signals and rate, and a client-side challenge that fingerprints headless browsers. What residential proxies fix, and what you have to bring yourself.

Radware Bot Manager scores your IP and cross-property reputation, a JavaScript Crypto Challenge, a 250-parameter device fingerprint, and your intent through IDBA. What a residential proxy solves there, and what you have to bring yourself.

Kasada is an invisible, CAPTCHA-free bot defense built around a client-side JavaScript challenge that only a real browser can run. We cover how it works, what residential proxies do and do not fix, and why it is one of the hardest walls.

Queue-it is a virtual waiting room, not a fingerprint wall. It throttles everyone, hands you an HMAC-signed pass token, and randomizes the queue for scheduled sales. So what actually helps you get through?

F5 Distributed Cloud Bot Defense, built on the Shape Security acquisition, leans on heavy client-side telemetry, behavioral analysis, and a network-wide signal set that retools when you do. Residential proxies cover one layer of that, and the rest is on your client.

PerimeterX, now HUMAN Bot Defender, builds a trust score from your IP, TLS fingerprint, a JavaScript sensor, and behavior, then shows a press-and-hold challenge when it doubts you. Residential proxies fix one input to that score. The rest you bring yourself.

Akamai scores your IP reputation, TLS and HTTP/2 fingerprint, an injected JavaScript sensor, and behavior into one per-request bot score. Residential proxies fix part of that, and you have to bring the rest yourself.

Imperva scores your IP, your TLS and browser fingerprint, and a JavaScript challenge into one bot verdict, then can drop a CAPTCHA when it doubts you. Residential proxies fix one part of that, and you have to bring the rest yourself.

Set up a free DeepSeek proxy for Janitor AI in minutes: get an API key, the proxy URL, and the model name, then fix the 429 quota and network errors for good.

ERR_PROXY_CONNECTION_FAILED means Chrome cannot reach your proxy at all. Six practical fixes, from a wrong port or dead proxy to a firewall or extension clash.

A 403 Forbidden through a proxy means the target blocked you, not that the proxy failed. Learn the real causes and how to fix them with clean IPs and headers.

A 407 Proxy Authentication Required error comes from the proxy, not the site. What causes it, and how to fix it fast in curl, with copy-paste tests.