Invalid response received

I have a spring boot backend webapplication. I use org.web3j core libary(4.5.5).
I create a web3j interface:

String ethereumBaseUrl = “”;

Web3j web3j = HttpService(ethereumBaseUrl + Constant.ETH_PUBLIC_KEY));

After that I check the connection the:


And I received the ClientConnectionException with a following message:
Invalid response received: 403; {“jsonrpc”:“2.0”,“id”:0,“error”:{“code”:-32600,“message”:“project ID is required”,“data”:{“reason”:“project ID not provided”,“see”:“”}}}

This code was working a few weeks ago.
What is wrong?
Thx for your help.

Hi @gergenye, you will need to use our latest v3 authentication format, you can signup at and get started on our free Core tier and get your updated URL.

Let me know if you have any questions!

1 Like

hi @mike , i received the 403 error message ( the different is that the error code is -32002), what can i do to deal with it ?

Hi @chenshuting524, and welcome to the Infura community! Can you paste in the full error message you’re getting, as well as the code you’re running when you get the error? That’ll help us debug this for you.