VS code containes emphasized items but no error

I'm writing a React project in VS code. I met this problem in VS code. In my project, this folder shows Contains emphasized items and I know it means there is a error in my files. But in the picture

,

I have checked all files but no error found. So this makes me feel confused.

I have search this problem in google and found a similiar github issue. https://github.com/Microsoft/vscode/issues/54960

Hope someone can help me. Thanks