microsoft/playwright · critical · Error

Error: unable to connect to a browser that does not have any

Error message

Error: unable to connect to a browser that does not have any contexts

What it means

Thrown when `--isolated` is not set and the resolved browser has zero contexts (`browser.contexts()[0]` is undefined). In non-isolated mode the CLI expects to reuse an existing context (e.g. a persistent profile or an attached/CDP server); a context-less browser cannot be driven, so startup aborts.

Source

Thrown at packages/playwright-core/src/tools/cli-daemon/program.ts:70

          await initWorkspace(options.initSkills, options.initSkillsGlobal);
          return;
        }

        setupExitWatchdog();
        const clientInfo = createClientInfo();
        const mcpConfig = await configUtils.resolveCLIConfigForCLI(clientInfo.daemonProfilesDir, sessionName, options);
        const mcpClientInfo = {
          cwd: process.cwd(),
          clientName: guessClientName(),
        };

        try {
          const { browser, browserInfo, canBind, ownership } = await createBrowserWithInfo(mcpConfig, mcpClientInfo, options);
          if (canBind)
            await browser.bind(sessionName, { workspaceDir: clientInfo.workspaceDir });
          const browserContext = mcpConfig.browser.isolated ? await browser.newContext(mcpConfig.browser.contextOptions) : browser.contexts()[0];
          if (!browserContext)
            throw new Error('Error: unable to connect to a browser that does not have any contexts');
          const persistent = options.persistent || options.profile || mcpConfig.browser.userDataDir ? true : undefined;
          const socketPath = await startCliDaemonServer(sessionName, browserContext, browserInfo, mcpConfig, clientInfo, mcpClientInfo, { persistent, exitOnClose: true, ownership });
          console.log(`Daemon listening on ${socketPath}\n`);
        } catch (error) {
          console.log(error);
          gracefullyProcessExitDoNotHang(1);
        }
      });
}

function defaultConfigFile(): string {
  return path.resolve('.playwright', 'cli.config.json');
}

function globalConfigFile(): string {
  return path.join(process.env['PWTEST_CLI_GLOBAL_CONFIG'] ?? os.homedir(), '.playwright', 'cli.config.json');
}

View on GitHub (pinned to c8fc3bf8d3)

Solutions

Pass `--isolated` so the CLI creates its own context on the remote browser.
Or ensure the target browser already has at least one context before connecting (create one on the server side).
Verify the `--cdp`/`--endpoint` URL points to a live browser process, not a shut-down one.

Example fix

// before
playwright-cli start --cd-endpoint ws://host:9222 --no-isolated
// after
playwright-cli start --cdp-endpoint ws://host:9222 --isolated

Defensive patterns

Strategy: validation

Validate before calling

// Decide isolated vs reuse based on whether the remote has contexts.
const browser = await connectToBrowser(url);
const hasContext = browser.contexts().length > 0;
if (!hasContext && !options.isolated)
  throw new Error('Remote browser has no contexts; pass --isolated or create one server-side.');

Try / catch

try {
  await startCli(session, opts);
} catch (e) {
  if (/does not have any contexts/.test((e as Error).message)) {
    opts.isolated = true; // retry with isolated
    await startCli(session, opts);
  } else throw e;
}

Prevention

Use --isolated when targeting a fresh launchServer/CDP endpoint.
For shared profiles, confirm a context exists server-side before connecting.
Treat a context-less remote as a hard error rather than assuming reuse.

When it happens

Trigger: Connecting via `--endpoint`/`--cdp` to a browser server that was started with `launchServer` (which exposes no contexts until one is created) while `isolated` resolves to false; or a persistent/attached path where context creation failed silently.

Common situations: Pointing `--cdp-endpoint` at a fresh `browserType.launchServer()` instance without `--isolated`; the MCP/CLI default `isolated=true` was overridden to false via config while using a remote endpoint that has no contexts; a stale CDP endpoint whose context was already closed.

Related errors

AI-assisted analysis of microsoft/playwright@c8fc3bf8d3 (2026-08-12). Data as JSON: /api/errors/bb9fb943648020c7. Report an issue: GitHub.