问为什么我的react应用程序在导入和使用material图标后显示一个空白屏幕，尽管在我的控制台中编译成功了？

EN

import React from 'react';
import { MdOutlineMenu } from 'react-icons/md';
import { FiSearch } from 'react-icons/fi';
import { MdVideoCall } from 'react-icons/md';
import { GrApps } from 'react-icons/gr';
import { IoIosNotifications } from 'react-icons/io';
import Avatar from '@material-ui/core/Avatar';

function header() {
  return (
    <div className='header'>
        <h1>I am a header</h1>
        <MdOutlineMenu />
        <img className='header__logo' 
        src="https://imgs.search.brave.com/0Adz0eT0KyLAofHJ_wU_1- 
        GqmHa0rnORMw9GWm__p0Q/rs:fit:844:225:1/g:ce/aHR0cHM6Ly90c2U0
        /Lm1tLmJpbmcubmV0/L3RoP2lkPU9JUC5f/SWZFYVVzc2paUXda/MXU5MmIxX0dnSGFF
        /SyZwaWQ9QXBp" alt="" />
        <input type="text" />
        <FiSearch />
        <MdVideoCall />
        <GrApps />
        <IoIosNotifications />
        <Avatar alt="Remy Sharp" src="https://avatars2.githubusercontent.com/u/24712956? 
        s=400&u=b71527e605ae1b748fc2d4157a842e57e427ad44&v=4"/>

    </div>
  );
}

export default header;