Claude Troubleshooting in Practice: Page Freezing, Login Loops, and Attachment Failures

If Claude won’t open, keeps spinning, messages won’t send, or attachments fail to upload, don’t rush to refresh repeatedly. Follow the troubleshooting steps below in order of “most common, most effective,” narrowing down the cause from browser environment to network and upload details—usually you can get back to normal within a few minutes.

Start with three basic checks to quickly rule out environment issues

When troubleshooting Claude, the first step is to sign in once in an incognito window to eliminate interference from extensions, cache, and abnormal sessions. If it works fine in incognito, then return to the original window, clear the site’s cache and cookies, and temporarily disable ad blockers and script-manager-type extensions. Finally, confirm your network: switch to a stable connection if possible, and avoid corporate proxies or public Wi‑Fi that can cause handshake failures or incomplete resource loading.

If the page is still blank or components won’t load, visit the official status page (status.anthropic.com) to confirm whether there’s a server-side disruption. When the server is having issues, continuing to tinker with local settings doesn’t help much; waiting and trying again after recovery is often faster—also the least effortful way to troubleshoot Claude.

Login loop, repeated redirects: most likely cookies and cross-site restrictions

In Claude troubleshooting, the common cause of “being sent back to the login page after logging in” is third-party cookies being disabled or overly strict browser privacy policies. First clear the site-related cookies, then allow cookies for the site in your browser settings, or switch to the default privacy level to test. If you use enterprise SAML/SSO login, make sure the identity provider page that pops up isn’t being blocked, and allow new windows and redirects.

Also, an incorrect system time can cause session validation to fail, showing up as repeated verification or outright rejection. Set your computer clock to sync automatically and try again—this often ends this kind of Claude troubleshooting immediately.

Message send failures, conversations getting stuck: check network and session status first

If it stays on “Sending” after you type or shows a failure prompt, Claude troubleshooting recommends copying what you just wrote first to avoid losing it on refresh. Then refresh the page and re-enter the conversation, or open a new chat to test: if the new chat works, the old session may be stuck in a previous generation. On the network side, focus on whether you’re frequently switching networks, whether a proxy is rewriting HTTPS, or whether you have multiple Claude tabs open at the same time causing session conflicts.

If failures happen more often with long text or complex instructions, try splitting it into two or three messages, and reduce pasting huge blocks of code all at once. This isn’t “downgrading usage,” but a more stable Claude troubleshooting approach that can effectively avoid occasional transmission interruptions.

Attachment upload failures or parsing issues: start with format, naming, and browser permissions

For attachment-related Claude troubleshooting, first check the UI prompt: file types and sizes are usually limited, and exceeding them will fail immediately or get stuck uploading. Rename the file using English letters/numbers, remove special characters, and try compressing or splitting it before uploading again; for images, export to common formats first and confirm the file isn’t corrupted. If it keeps spinning during upload, try a different browser or disable “block cross-site tracking/enhanced protection” and try again—often the upload domain is being blocked.

If uploads always fail in a corporate environment, suspect that a gateway/security software is restricting the upload channel. In that case, the most effective Claude troubleshooting is to test on a personal network—one try can tell whether it’s a local machine issue or a network policy issue.