After "yarn global upgrade generator-jhipster", the version is 4.14.5 instead of latest version 5.3.4. why?

My node version is 8.11.1, yarn is 1.3.2.

2 possibilities:

• when you run jhipster --version it prints local version (from local node_modules folder) if your are in a generated project, this enables projects to isolate from each others. In this case you must upgrade the project with jhipster upgrade
• when you are not in a generated project, jhipster --version prints globally installed version and it probably means that you have installed jhipster twice (once with yarn and once with npm)

Usually the fix to double global installation is to uninstall from npm and yarn then reinstall with one or the other:

Remove from both yarn and npm

yarn global remove generator-jhipster
npm uninstall -g generator-jhipster

Install with just npm

npm install -g generator-jhipster

Since JHipster 5.3.0 npm is now the default client package manager, instead of Yarn.

Check version

jhipster --version
Using JHipster version installed globally
5.3.4