If the page just spins or throws a connection error, start with the basics: clear your browser cache, try a different browser, or open an incognito window. Sometimes a stale cookie breaks the session entirely. If that doesn't help, check whether your ISP is having routing issues — traceroute to lichess.org will show where packets are dropping.
Lag during games is usually a local network issue, not the server. A few things worth checking:
Failed login most often comes down to a wrong password or an expired session cookie. Reset your password through the official form, then fully log out and back in. If two-factor authentication is enabled and your authenticator app is out of sync, recalibrate the time settings on your device — TOTP codes are time-sensitive.
The board stops responding mid-game for a few reasons. WebSocket disconnection is the most common — the site relies on a persistent connection, and any network hiccup breaks it. Reload the page and reconnect. If freezes happen regularly, disable browser extensions one by one; ad blockers and script managers sometimes interfere with the WebSocket handshake.
The Lichess app occasionally fails to sync game history or crashes on startup after an OS update. Force-close the app, clear its cache in your phone settings, and relaunch. If the problem persists after reinstalling, check that your OS version is still supported — older Android and iOS builds sometimes get dropped after major app updates.
If the puzzle trainer or computer analysis just shows a blank board, the issue is usually JavaScript failing to initialize. Disable any content blockers for the domain, make sure JavaScript is enabled, and try reloading. On slower connections, the engine worker file (Stockfish WASM) can time out before it fully loads — a stable connection and a bit of patience usually fixes it.