调整

app/controllers/courses_controller.rb

@@ -106,8 +106,6 @@ class CoursesController < ApplicationController
     if params[:category_id].present? && params[:category_id].to_i != 0
       videos = videos.where(course_second_category_id: params[:category_id].to_i)
     end
-    @category = @main_category.course_second_categories.find_by(id: params[:category])
-    tip_exception("子目录id有误") if !@category.present?
 
     videos = custom_sort(videos, params[:sort_by], params[:sort_direction])
     @count  = videos.count