old_contents: import os
  
  from django.shortcuts import render
  from django.http import HttpResponseNotFound
  from django.contrib.staticfiles import finders
  
  
  def view_presentation(request, filename):
      # Find the file in staticfiles.
      full_path = finders.find(os.path.join("presentation", filename + ".htm"))
  
      if not os.path.exists(full_path):
          return HttpResponseNotFound("Unknown presentation name: " + filename)
  
      with open(full_path) as presentation_file:
          presentation_html = presentation_file.read()
  
      return render(request, "presentation/view.dj.htm", {
          "presentation_html": presentation_html,
      })
  
new_contents: import os
  
  from django.shortcuts import render
  from django.http import HttpResponseNotFound
  from django.contrib.staticfiles import finders
  
  
  def view_presentation(request, filename):
      # Find the file in staticfiles.
      full_path = finders.find(os.path.join("presentation", filename + ".htm"))
  
      if not full_path or not os.path.exists(full_path):
          return HttpResponseNotFound("Unknown presentation name: " + filename)
  
      with open(full_path) as presentation_file:
          presentation_html = presentation_file.read()
  
      return render(request, "presentation/view.dj.htm", {
          "presentation_html": presentation_html,
      })
  
  
subject: Fix a path issue