I am new to blockchain and trying Playground for my first Blochain application. I followed this tutorial.
As soon as I click "deploy", I get a pop-up on screen saying "error:error trying install business network. Error: The business network is already installed on all the pears.
Any help will be highly appreciated!!
You would be better off not using hyperledger composer, it's been end of life for a long time and no one uses it and so there won't be anyone who will be able to help you or willing to invest any time to help you. I would suggest you look at hyperledger fabric (which hyperledger composer used to require to provide the blockchain capability as hyperledger composer is not a blockchain technology but an application framework).
https://hyperledger-fabric.readthedocs.io/en/latest/
Also this guide may be useful
https://github.com/hyperledger/fabric-samples/tree/main/full-stack-asset-transfer-guide