main.js

//vue版本为3.5.13
import { createApp } from 'vue'
import './style.css'
import App from './App.vue'
import 'element-plus/dist/index.css'
import router from './router/index'

const app = createApp(App)

app.use(ElementPlus)
app.use(router)
app.mount('#app')

vite.config.js

// vite版本6.0.1
import { defineConfig } from 'vite'
import AutoImport from 'unplugin-auto-import/vite'
import Components from 'unplugin-vue-components/vite'
import { ElementPlusResolver } from 'unplugin-vue-components/resolvers'
import vue from '@vitejs/plugin-vue'

export default defineConfig({
  // ...
  plugins: [
    // ...
    AutoImport({
      resolvers: [ElementPlusResolver()],
    }),
    Components({
      resolvers: [ElementPlusResolver()],
    }),
    vue(),
  ],
})

index.js

//router版本4.5.0
import { createRouter,createWebHistory } from "vue-router";
import HelloWorld from '../components/HelloWorld.vue';
const router = createRouter({
    history:createWebHistory(),
    routes:[
        {
            path:'/',
            component:HelloWorld,
        },
    ]
})
export default router;

版本不匹配可能会出现报错，或者前端页面不显示的问题。而且vue版本不同配置文件也会有所差别，出现问题建议检查是否为版本问题