bitcoin core test config error I tried configuring the bitcoin core test by editing the bitcoin.conf file with the required credentials.

Earlier, before the writing the test credentials it was a running full node.
now the error is 

config settings for rpcport only applied on the test network when in [test] section.

(picture uploaded for reference)
Since you are choosing to use network specific sections in your config file, Core requires you to have certain arguments in those sections, such as rpcport. So you need to move rpcport into a network specific section.