我终于明白了！我具有.Net Core Windows Server Hosting捆绑包的过时版本.我安装了2.1.1版.我删除了它，并安装了版本2.1.4，现在可以使用了.感谢大家的时间和支持.我真的很感激！

I finally figured it out! I had an outdated version of the .Net Core Windows Server Hosting bundle. I had version 2.1.1 installed. I removed it, and installed version 2.1.4 and now it works. Thanks everyone for your time and support. I really appreciate it!