After the release of .net core 2.1, hostingModel="inprocess" does not appear in web.config, no problem。
After the release of .net core 3.1, delete hostingModel="inprocess" and you can browse normally。
Ask what causes it, I want to solve this problem
<aspNetCore processPath="dotnet" arguments=".\NewDeBao.OfficeApplication.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
As far as I know, before asp.net core 2.2, ASP.NET Core apps run in a process separate from the IIS worker process, the module also handles process management. The asp.net core apps are running at the Kestrel.
But starting with 2.2, the asp.net core module uses an in-process server implementation for IIS. The in-process hosting model isn't supported for ASP.NET Core apps that target the .NET Framework. I guess this may caused your issue.
To solve this issue, you could try to host asp.net core as OutOfProcess as asp.net core 2.1.
More details, you could refer to below web.config setting: