Metamask not connecting to localhost 8545 - blockchain

Question

I was trying to follow a tutorial from devto.io and to send transactions to the smart contract, I would need to connect my MetaMask wallet using one of the accounts created when I ran npx hardhat node command.
To do so, I opened MetaMask and updated the network to be Localhost 8545, but Metamask didn't connect to it and showed errors like the following screenshot.

Answer 1

I think that you probably interrupted the node you launched when you typped :
npx hardhat node
You should keep it running, open another terminal for the rest of the tutorial.
Also you could check the output of this command. Is it indicating something else than ? :
Started HTTP and WebSocket JSON-RPC server at http://127.0.0.1:8545/

Answer 2

You most likely entered wrong URL into RPC-URL input: "http://localhost:8545". SInce in config file, hardhat has chainId:1337, it may be using ganache under the hood.
If you entered correct config but it still does not connect, you could use ganache-cli. http://localhost:8545 is for ganache-cli. You should be installing ganache-cli globally and then start the server on terminal if your hardhat node has an issue
ganache-cli
When you run the command on the terminal, you will get the local public and private keys:
After setting the network you could import an account in one of those private keys:
if you click on the logo next to the network name, you will see the option import account. note that everytime you run a new command ganache-cli it will generate new private keys, so you have import a new account.
ganache gui listens to "7545" but ganache-cli listens to "8545"

Answer 3

What worked for me, in this case, is This video
I downloaded Ganache from the following link
Installed it and just hit the Quick Start
It will launch the ganache as shared below in the screenshot. You can see the Network ID and RPC Server details.
As a Next step, delete the HTTP://localhost:8545 network and create a new network with Ganache RPC Server details and Network ID as shared below. I have just changed my port from default to 3000.
Here you Go!
Hope it helps. Also, feel free to share your thoughts if you have other approaches as I am also in the learning phase :-)
Thanks.

Answer 4

What helped me was following these steps :
Step 1: Install Ganache and then launch the application.
Step 2: Check the RPC SERVER on the navigation bar and note it down.
Step 3: Open Metamask network settings. Delete the original localhost network.
Step 4: Add a new Ganache localhost network with the following configuration:
Network name - Whatever you want (Example: Ganache localhost)
New RPC URL - RPC server noted from Ganache.
Chain ID - 1337
Currency Symbol - ETH
Press Add network

Answer 5

You probably have a IPv6 address that is not listening on that port.
e.g.
$ ping localhost
PING localhost.localdomain (::1)...
either remove that line from /etc/hosts (e.g. ::1 localhost.localdomain localhost) or point ethermask to 127.0.0.1 instead of localhost

Answer 6

The error is most simple that you probably think, the default chain id for test networks in metamask is not the same as the hardhat chain id, you should go to metamask, then config, networks, localhost and change chain id to 31337