Common Causes of 'Cannot POST' and 'Cannot GET' Errors in Express.js

In the HTTP/HTTPS web server package library “express.js” for the Node.js programming language, this article covers countermeasures, prevention methods, and causes when “Cannot POST” (Cannot GET) errors occur.

If you don’t specify a return value with res.send() as shown below, you’ll get a Cannot POST error when making an HTTP request.

app.all('/configall', function (req, res, next) {
  console.log('Accessing the secret section ...')
  next() // pass control to the next handler
})

curl http://192.168.0.110:8111/configall

You should write res.send() somewhere. The error is a bit unclear.

app.all('/configall', function (req, res, next) {
  console.log('Accessing the secret section ...')
  res.send("something here.")
  next() // pass control to the next handler
})

curl http://192.168.0.110:8111/configall

This way, if you write res.send(), the Cannot POST error will no longer occur.