Ethereum developer || Zero to hero

This error is usually caused by connecting web3 to the wrong port. For instance, my testrpc was : Listening on localhost:8545 But, I was trying to connect to it with the wrong port : var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8454"));

I ran into this issue when trying to compile the code, using 'truffle compile'. The error arises from the fact that there's a file in the project folder called 'truffle.js' and that's the one that Windows cmd tries to run when executing the command.  The simplest way to fix the issue is to use git bash to run 'truffle compile' - no runtime errors!