课程管理-单集 上传新视频后，点击保存，重新打开发现老视频仍然存在.

src/views/biz/course/detail.vue

@@ -1111,7 +1111,12 @@ export default {
             this.teacherModalVisible = true;
         },
         showVideoUploadModal() {
-            this.videoUploadModalVisible = true;
+            if(this.step1FormModel.type === 'SINGLE' && this.videoSeries.length>0){
+                this.$message.error("课程类型为单集,请先删除已有视频文件");
+                return;
+            } else {
+                this.videoUploadModalVisible = true;
+            }
         },
         closeVideoUploadModal() {
             this.videoUploadModalVisible = false;