Signature has zero size. Solution to the error

When I got off work, a colleague suddenly asked me how the company website broke down? I said it was impossible. I used it again just now. My colleague said, come and have a look. As a result, I entered the login URL skillfully. The common error pages in. Net were highlighted, with black characters on the yellow background and signature has zero size. -_-!
Because I have never encountered this mistake before, I thought it was the same as the previous mistake. I can certainly solve it with three axes.) First, replace it with the correct one.Program(Passed on the local machine), does not work -_-!. Restart IIS, but it still does not work -_-!!. Restart the framework (aspnet_regiis.exe-IR), but it still does not work -_-!!!, Several times later, I restarted the machine and continued the above steps. Finally, I was in a hurry @ _ @. I searched for the machine in Google, and found no result. Sigh seems like I had to solve it myself.
I suddenly remembered that when I updated the program at noon, there was a problem with. Net Automatic Registration? Why does copying a new program not solve the problem? I still think it is a bit strange that the dead horse is a dead horse doctor. I may delete the program directory corresponding to this virtual directory so that. NET will not register it back, just do it. First, delete the virtual directory, and then delete the program file. To be safe, restart the machine. Copy the new program, create a virtual directory, and log on again. Haha, you can finally log on ^-^!

I am writing it here. As a solution to this problem, there is no more authoritative explanation on the Internet. I hope to give a reference to my friends who have encountered this problem. I am very happy to have a good explanation or solution, don't hesitate to enlighten me!