As Svenmarim already stated, this mostly occurs because the ip adress is already in use. This answer and its comments from the visualstudio developer community pointed me to the right direction. In my case i was trying to access my local IISExpress instance from my local network and therefore binded my ip adress with the same port which uses my IISExpress instance via netsh http add urlacl url=http://192.168.1.42:58938/ user=everyone After removing this binding via netsh http delete urlacl url=http://192.168.1.42:58938/ it worked again.

我刚刚将我的配置文件从“IIS Express”更改为“MyProjectName”(我认为是使用kestrel作为http服务器而不是IIS)，现在它工作正常:

As Svenmarim already stated, this mostly occurs because the ip adress is already in use. This answer and its comments from the visualstudio developer community pointed me to the right direction. In my case i was trying to access my local IISExpress instance from my local network and therefore binded my ip adress with the same port which uses my IISExpress instance via netsh http add urlacl url=http://192.168.1.42:58938/ user=everyone After removing this binding via netsh http delete urlacl url=http://192.168.1.42:58938/ it worked again.

这个问题可能是因为[√]为你的项目选择了启用SSL(参见项目设置窗口中的调试选项卡)，但Visual Studio决定傻傻地设置像http://localhost:32396这样的东西。失败的原因是1。它不是HTTPS;证书无效。要强制执行，您需要使用44300-44398范围内的端口。

参见https://stackoverflow.com/a/24957146/1236397

首先:从项目中删除。vs文件夹(撇开。sln文件)，然后打开项目。

祝你好运

我不知道是什么导致了这个问题。 但是修理装置把它修好了。