After copying the vue project, why are there still modules not installed after npm insatll?

  node.js, question

1. for example, there is a vuenit webpack projecta created by vue. after all npms are installed, you can use npmrundv.

2. After I copied Project A to projectB, I executed npm install. After npm run dev still indicated that many modules did not exist and needed to be installed. Then I could only install one by one, and I could install whatever npm indicated.

Is there any way to solve it all at once?

Delete the node_modules folder and reinstall npmsTALL.