Claude Troubleshooting: Fixing Message Send Failures, 500/502 Errors, and Login Redirect Loops

When using Claude, the most infuriating thing is usually not “the answers aren’t good,” but that messages won’t send, the page throws 500/502 errors, or the login keeps redirecting in a loop. This article follows the sequence “first confirm external outages → then check the local environment → finally handle account and permission issues” to compile a practical set of Claude troubleshooting steps. Follow them and you can usually narrow down the problem quickly.

Do two things first: check service status and the network path

Before starting Claude troubleshooting, open Anthropic’s service status page (status.anthropic.com) to see whether there’s an incident or maintenance; if it’s red there, there’s little point in tinkering locally. Next, test with a different network path: open Claude using your phone’s hotspot, or access it from a different device on the same network, to confirm whether the problem is limited to the current browser or network.

If you’re in an environment where network quality fluctuates, Claude is more likely to time out or get stuck on “Sending.” In that case, the priority isn’t repeatedly refreshing, but stabilizing the connection: switch to a cleaner network, disable proxies/acceleration tools that degrade the connection, and make sure your system time is set to sync automatically.

Message send failure / endless spinning: start with the browser environment

If Claude shows a message send failure or the input box becomes unresponsive after you submit, the most common causes are browser cache, extensions, or abnormal cookies. Try opening Claude in an incognito window; if it works normally there, go back to your regular window, clear cookies and cache related to claude.ai, then sign in again.

Also check extensions: ad blockers, script managers, and privacy/anti-tracking plugins can easily block Claude’s requests. During Claude troubleshooting, you can temporarily disable all extensions and then re-enable them one by one to find the culprit; additionally, switching to the latest Chrome/Edge often bypasses compatibility issues directly.

Seeing 500/502/gateway errors: avoid the “hard refresh” trap

Errors like 500/502 are more like transient server-side or network-path fluctuations, and frequent hard refreshes may instead trigger stricter protection mechanisms. The correct troubleshooting approach is: wait 1–3 minutes and try again, and don’t submit multiple messages rapidly in succession during that time.

If 502 keeps happening, try changing DNS (e.g., switch to a common public DNS), change your network egress (hotspot/another broadband line), and reduce concurrent actions: close extra tabs and stop repeatedly uploading attachments. If the conversation content is very long, it’s also recommended to split it into multiple messages to reduce the load per request—Claude is usually more stable that way.

Repeated login redirects / verification failures: address cookies and region/risk-control issues

If the Claude login page keeps looping through redirects, it’s mostly due to conflicts in login-state cookies: sign out, clear cookies related to claude.ai and anthropic.com, then log in again. If you switch between multiple accounts, it’s also recommended to keep only one account signed in to avoid an old session kicking out a new one.

If you’re prompted that the service can’t be used or verification is abnormal, consider region and risk-control restrictions: Claude may be unavailable in some regions or network environments, so be sure to access it from an officially supported region and a compliant network. If it still doesn’t work after completing the above troubleshooting, you can submit a ticket via the help entry on the page, attaching an error screenshot, the time it occurred, your browser version, and network type—this is usually easier to pinpoint quickly.