调整

app/views/subjects/_new_or_edit.html.erb

@@ -106,7 +106,7 @@
         placeholder: "请在此输入实训课程的学习须知",
         imageUpload : true,
         imageFormats : ["jpg", "jpeg", "gif", "png", "bmp", "webp", "JPG", "JPEG", "GIF", "PNG", "BMP", "WEBP"],
-        imageUploadURL : "<%= upload_with_markdown_path(:container_id => @subject.id, :container_type => @subject.class) %>" //url
+        imageUploadURL : "<%= upload_with_markdown_path(:container_id => @subject.id, :container_type => 'MarkDown') %>" //url
     });
     md_elocalStorage(shixun_propaedeutics, "subject_notes_<%= User.current.id %>", "notes");