Render json with jbuilder, "\x90" from ASCII-8BIT to UTF-8, locale issue?

Question

Ruby on Rails

I display a graph using morrisjs and get an error when rendering the view

"\x90" from ASCII-8BIT to UTF-8

The chart output code

<%= content_tag :div, "", id: "study_chart", data:{studyes: @studyes} %>

Controller

class StudyesController < ApplicationController
  before_filter :authenticate_user!, :except => [:some_action_without_auth]
#  before_action :set_patient, only: [:show]
  respond_to :json, :html
  def index
    #@studyes = Study.all

    @studyes = Study.paginate(:page => params[:page], :per_page => 10)

     logger.debug
    respond_with(@studyes)
  end
  private
  def studyes_params
    params.require(:study).permit( :study_iuid, :study_id, :study_desc, :mods_in_study, :num_series, :num_instances, :retrieve_aets, :patient_fk)
  end
end

Google only talks about the wrong locale, a problem in the muscle driver, or use force_encoding. I have a postgres database and everything is fine with the locale.

Answer 1

Well, they also write to update rdoc. Did a bundle update, didn't help.