Invalid config for [mqtt]: expected a dictionary for dictionary value @ data[‘mqtt’]. Got ‘broker:192.168.1.150 port:1883 client_id:homeassistant username:username password:bunty@123’. (See ?, line ?). Please check the docs at https://home-assistant.io/components/mqtt/
First things first. In YAML, spacing is EXTREMELY important. You have posted an invalid configuration, based on spacing alone. Please post your ACTUAL code with the code tags, and you do have a broker running at that IP address, right?