1. I happily finished breakfast in the morning, typed a few lines of code, and prepared to debug. I found that the VS debugging project opened very slowly, and finally reported an error as shown below.
2. Then it is likely to be an IIS problem. After restarting IIS, it still does not work. Enter localhost in the address bar, as shown in the figure below (my win10 system). Obviously, IIS is no problem.
3. Our project is no problem, and IIS is no problem, so what is the reason. I followed the advice of others and went to ping localhost , as shown below
4. Obviously the IIS service is blocked, just follow the online method, turn off the firewall, and then it's fine! ! !