我正在尝试安装和配置Umbraco 8。 NuGet会很好地安装umbracoCms，然后我运行该应用程序以配置数据库（自定义数据库）。
它崩溃并显示：
Error during installation
See the log for full details (logs can typically be found in the App_Data\Logs folder)
日志说明不了什么
{"@t":"2019-04-24T04:04:00.1230739Z","@mt":"An error occurred in InstallStatus trying to check upgrades","@l":"Error","@x":"System.NullReferenceException: Object reference not set to an instance of an object.\r\n at Umbraco.Web.Install.InstallHelper.GetDbProviderString(ISqlContext sqlContext)\r\n at Umbraco.Web.Install.InstallHelper.InstallStatus(Boolean isCompleted, String errorMsg)","SourceContext":"Umbraco.Web.Install.InstallHelper","ProcessId":1180,"ProcessName":"iisexpress","ThreadId":13,"AppDomainId":3,"AppDomainAppId":"LMW3SVC2ROOT","MachineName":"Machine1","Log4NetLevel":"ERROR","HttpRequestNumber":4,"HttpRequestId":"{requestguid}"}
DB连接串是正确的，尽管从错误消息中我无法确定这是DB或应用程序有问题，但是正在创建数据库表。
Umbraco 7.10也发生了同样的事情。
我正在VS 15.9.11和MSSQL 2016的.NET 4.7.2上运行项目