WebSocket connection to 'ws://127.0.0.1:9944/' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED Provider.js:380

In the substrate-front-end-template folder, I cmd’d yarn add @polkadot/api

---

CHROME

The node runs in one tab of my browser, but a new tab with the same URL comes up which gives me the error:

Error Connecting to Substrate
Error: FATAL: Unable to initialize the API: createType(StorageKey):: Derived TypedArray constructor created an array which was too small

In the console:

WebSocket connection to 'ws://127.0.0.1:9944/' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED
Provider.js:380

---

FIREFOX

I got only one tab, with a different error written:

Error Connecting to Substrate

Error: FATAL: Unable to initialize the API: createType(StorageKey):: expected TypedArray of at least length 4, but constructor returned TypedArray of length 0

Console:

API/INIT: Error: FATAL: Unable to initialize the API: createType(StorageKey):: expected TypedArray of at least length 4, but constructor returned TypedArray of length 0
Init.js:85

---

I read your closed thread about this error, and I assume it’s not an easy one to trace, so hopefully my excessive information can help you.

[jacogr]

Yes, you can manually fix it - I would always recommend the latest stable version in the case 2.2.1 - https://github.com/polkadot-js/api/releases

Just ensure you change both the @polkadot/api & @polkadot/types lines (they always go hand-in-hand). After that, do a yarn and it should be ok.

[polkadot-js-bot]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue if you think you have a related problem or query.