You will not be able to go the rails console. Go to the root directory of the rails project and fire up an irb session:
1. require 'yaml'
2. YAML::ENGINE.yamler = 'psych'
3. YAML.load_file('config/your-config-file.yml')
Autocorrect yaml file syntax errors: s.gsub!(/\t/, ' ')
This will reproduce the problem. See the line number of row to find the syntax error. Fix it by changing the tab to space.