Use the flex Shorthand Property-BUG: Cannot read property 'length' of null

Tell us what’s happening:

Your code so far

  #box-container {
    display: flex;
    height: 500px;
  #box-1 {
    background-color: dodgerblue;
    display: flex;
    flex-grow: 2;
    flex-shrink: 2;
    flex-basis: 150px;
    height: 200px;

  #box-2 {
    background-color: orangered;
    display: flex;
    flex-grow: 1;
    flex-shrink: 1;
    flex-basis: 150px;
    height: 200px;

<div id="box-container">
  <div id="box-1"></div>
  <div id="box-2"></div>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:

Read the instructions again.

You should use short-hand property instead of explicitly declaring them. For ex.

flex: 1 0 10px;

It’s work!!! Thanks for your help!