There have been numerous bugs in the express-session module that can cause issues with node.js session management. Here are some common errors:

1. Session Not Initialized Properly: If you don't initialize your express-sessions, it won't store any data and will just throw an error.

var session = require('express-session');
app.use(session({ secret: 'secret', saveUninitialized: true, resave: false }));

2. Cookie Parsing Error: The express-sessions module depends on cookie-parser to parse the cookies which have to be initialized before session middleware.

var cookieParser = require('cookie-parser');
app.use(cookieParser());
app.use(session({ secret: 'secret', saveUninitialized: true, resave: false }));

3. Session ID Injection: The session id can be injected into the client browser if it is not sanitized properly.

var express = require('express');
app.use(express.urlencoded({ extended: true }));
app.get('/login', function(req, res) {
  res.render('login', { session_id: req.sessionID });
});

4. Session Cookie Tampering: The session cookie can be tampered with if it is not validated properly.

var express = require('express');
app.use(express.json());
app.get('/logout', function(req, res) {
  if (req.sessionID === req.body.session_id) {
    req.session.destroy();
    res.send({ message: 'Logged out' });
  } else {
    res.status(403).send({ message: 'Invalid session id' });
  }
});

5. Session Timeout Issues: The session cookie may expire before the user is logged out, which can lead to unexpected behavior.

app.use(session({ secret: 'secret', saveUninitialized: true, resave: false, maxAge: 60 * 1000 })); // 1 minute

To fix these issues, you should make sure that you initialize the session properly and use cookie-parser. You should also validate the session id before using it, and ensure that the session cookie has a proper timeout.