Psych::SyntaxError: (

I'm trying to rest my rails db or drop the db and aways show this message, please someone have any idea what this" Psych::SyntaxError: (): mapping values have to do with the db?

thank's

Psych::SyntaxError: (<unknown>): mapping values are not allowed in this context at line 28 column 9
/Users/danielcalixto/vitrineonline/config/environment.rb:5:in `<top (required)>'
Tasks: TOP => db:reset => environment