ruby-on-rails – Rails 3.1升级后的ActionView :: MissingTemplate

在升级到Rails 3.1.0和 David Rice’s instructions之后,我的所有控制器都奇怪地找不到他们的意见了.

# rails s #

Started GET "/units" for 127.0.0.1 at 2011-09-04 07:52:23 -0400
  Unit Load (0.1ms)  SELECT "units".* FROM "units" 

ActionView::MissingTemplate (Missing template units/index,application/index with {:handlers=>[:erb,:builder],:formats=>[:html],:locale=>[:en,:en]}. Searched in:
):
  app/controllers/units_controller.rb:9:in `index'

units_controller.rb：

# GET /units
  # GET /units.xml
  def index
    @units = Unit.all

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @units }
    end
  end

当然,视图在那里(/app/views/units/index.html.erb;它在升级之前工作).我觉得这是一个愚蠢的错误,我在这里错过了什么？