webviz: Error when conneting to rosbridge after running static-webviz

After building the dependencies and running npm run serve-static-webviz, then typing http://localhost:8080/ in Chrome, it can directly lead to the application page, rather than run http://localhost:8080/app one more time as before. But if I run rosbridge afterwards, the application page will throw an error out. The details are shown in the following screenshot. Does somebody know, what is the reason for the error, and how can I solve it? Thanks in advance.