I'm getting this error when i try to create a "Lecture" via my Lecture controller's create method. This used to work but i went on to work on other parts of the app & then of course i come back & something is now throwing this error when a user tries to create a Lecture in my app.

I'm sure its something small i'm just overlooking (been at it a while & probably need to take a break)...but I'd appreciate if someone could let me know why this is happening...let me know if i need to post anything else...thx!

The error I get

NoMethodError in LecturesController#create

undefined method `save' for nil:NilClass
Rails.root: /Users/name/Sites/rails_projects/app_name

Application Trace | Framework Trace | Full Trace
app/controllers/lectures_controller.rb:13:in `create'

My view to create a new Lecture

views/lectures/new.html.erb

<% provide(:title, 'Start a Lecture') %>

<div class="container">
  <div class="content-wrapper">

    <h1>Create a Lecture</h1>

     <div class="row">
       <div class="span 6 offset3">
         <%= form_for(@lecture) do |f| %>
           <%= render 'shared/error_messages', :object => f.object %>
           <div class="field">
             <%= f.text_field :title, :placeholder => "What will this Lecture be named?" %>
             <%= f.text_area :content, :placeholder => "Describe this Lecture & what will be learned..." %>
           </div>
          <%= f.submit "Create this Lecture", :class => "btn btn-large btn-primary" %>
         <% end %>
       </div>
     </div>
   </div>
 </div>

Then my controller where its saying the error is coming from

controllers/lectures_controller.rb

class LecturesController < ApplicationController
before_filter :signed_in_user, :only => [:create, :destroy]
before_filter :correct_user,   :only => :destroy

def index
end

def new
  @lecture = current_user.lectures.build if signed_in?
end

def create
  if @lecture.save
   flash[:success] = "Lecture created!"
   redirect_to @lecture
  else
   @activity_items = [ ]
   render 'new'
  end
end

def show
 @lecture = Lecture.find(params[:id])
end

def destroy
  @lecture.destroy
  redirect_to root_path
end


private

  def correct_user
    @lecture = current_user.lectures.find_by_id(params[:id])
    redirect_to root_path if @lecture.nil?
  end