fix #502

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/SearchCacheFilesOperation.cs

@@ -92,9 +92,16 @@ namespace YooAsset
                     if (_fileSystem.AppendFileExtension)
                     {
                         string dataFileExtension = FindDataFileExtension(chidDirectory);
-                        if (string.IsNullOrEmpty(dataFileExtension) == false)
+                        if (string.IsNullOrEmpty(dataFileExtension))
+                        {
+                            //注意：覆盖安装的情况下，缓存文件可能会没有后缀格式，需要删除重新下载！
+                            dataFilePath = string.Empty;
+                        }
+                        else
+                        {
                             dataFilePath += dataFileExtension;
                         }
+                    }
 
                     var element = new VerifyFileElement(_fileSystem.PackageName, bundleGUID, fileRootPath, dataFilePath, infoFilePath);
                     Result.Add(element);