Claude Troubleshooting Practical Manual: Handling Login Restrictions, Send Failures, and Attachment Issues

When using Claude, running into login failures, messages that won’t send, or attachment upload failures is often not as simple as “the system is broken.” Below, common issues are broken down and checked in order of frequency, aiming to help you pinpoint the cause and restore usability within minutes.

First, determine whether there’s a Claude server-side disruption

When you see a page message like “Something went wrong” or an endless loading spinner, don’t rush to change settings. It’s recommended to open Claude’s official website first, then visit its status page (status.anthropic.com) to confirm whether there is a widespread outage or degradation.

If the status page shows anomalies, the most effective approach is to wait and reduce repeated refreshing; frequent retries may trigger temporary risk controls. After the status recovers, log back in to Claude—things usually return to normal automatically.

How to handle Claude login restrictions and a stuck verification code

Common causes of Claude login failures include an unstable network environment, browser cache conflicts, or extensions blocking verification scripts. First, try logging in to Claude in an incognito/private window, and temporarily disable ad blockers and script-management extensions.

If the verification code never appears, switching to a different browser engine is often faster (for example, switching from one Chromium-based browser to another). Also check whether your system time is set to sync automatically—time drift can cause Claude’s security checks to fail.

Message send failures, conversation interruptions, and rate limits

During high-frequency consecutive sends, Claude may impose a brief rate limit or queueing, which can look like the send button being unresponsive or a “try again later” prompt. In this case, reduce your sending frequency, combine questions into a single prompt, and wait a minute or two before continuing.

If only one conversation thread is abnormal, create a new chat to verify whether “only this session is broken.” In addition, network jitter can interrupt Claude’s streaming output; switching to a more stable network (or temporarily disabling proxy split-tunneling rules) is usually more effective.

Attachment upload failures: format, size, and browser blocking

The most common reasons Claude attachments fail are that the file is too large, the format isn’t supported, or the upload process is blocked by browser privacy/security policies. First, compress or split the file, or convert it to a more widely supported format, then upload it to Claude again.

If you’re using Claude on a corporate network, the gateway may block upload requests; in that case, testing with a mobile hotspot is the most straightforward. It’s also recommended to clear the site cache and retry, to avoid failures caused by an old upload session being held.

Still not resolved: hand it off to official support via the shortest path

If you’ve confirmed it’s not a server-side outage and Claude is still unusable after switching networks and browsers, it’s recommended to go directly through the official support channel. When submitting, include: a screenshot of the error, the time it occurred, your browser version, a description of your network environment, and whether it reliably happens in a specific conversation or with a specific file.

Doing so can significantly reduce back-and-forth communication time and make it easier for the Claude support team to reproduce the issue and provide a targeted solution.