一.參考CU13 toCU21更新作法如下
1. Upgrade from CU13 to CU15 to gain support for .NET 4.6.2
2. Install .NET 4.6.2
3. Upgrade from CU15 to CU20 to gain support for .NET 4.7.1
4. Install .NET 4.71
5. Install VC++ 2013 run-time library
6. Upgrade from CU20 to CU21