Claude FAQ: Fixing Session Timeouts & Model Selection Errors

As one of the most popular AI assistants, Claude often frustrates users with session timeouts and model selection mismatches. This article covers three most annoying failure scenarios along with actionable steps you can follow without searching through help centers.

What to Do When a Session Times Out

Claude sessions typically have an idle time limit. After a long pause or a network fluctuation, when you try to send a new message, the interface may show "Connection lost" or simply go blank. Don't rush to refresh the page. First, try clicking the "New conversation" button at the bottom of the page to rebuild the session.

If timeouts happen frequently, check your network stability or switch to the officially recommended Chrome browser. Also, avoid dumping dozens of screens of content in a single long chat—splitting your questions into smaller chunks reduces server load.

How to Fix Model Selection Errors

When switching between Claude models (e.g., Sonnet, Haiku), you might occasionally see a popup like "Current model unavailable" or "Please select a valid model." This is usually due to account permissions or the API key being tied to the wrong plan tier. Free accounts only support Haiku; if you select Sonnet, it will throw an error.

The fix is simple: manually switch back to Haiku in the settings, or check your subscription plan on the official website. Pro users who still see the error can log out and log back in to refresh the model list. Also, avoid having multiple Claude tabs open at the same time, as it can cause model allocation conflicts.

How to Recover Lost Chat History

Many users report that Claude's conversation history suddenly disappears, especially after switching devices or clearing browser cache. First, open the "History" section in the left sidebar to see if it's just collapsed. If it's really missing, double‑check you're logged into the same account—logging in with a Google account and with an email creates two separate accounts.

Claude does not automatically back up conversations, so we recommend manually exporting important chats regularly (copy‑and‑paste or use a browser extension). Enterprise users can contact their admin to check backend logs. For free‑tier users, there's no recovery once the history is gone—so don't count on automatic restoration.