Hello! And welcome to the community. 
Because you have written your post in the Chinese language, I need to ask - are you using WeMod from China?
Because if you are, you will need to use a VPN in order to use most westen gaming services, such as WeMod. Because the Chinese government has chosen to censor many western gaming services.
Otherwise, the issue you are getting is also caused by security programs on your machine. See this post for the full troubleshooting steps: I can’t Install WeMod / "There was a error installing the application" - #2 by Ravenfyre.