title: Discord.js MessageEmbed field values must be non-empty strings
body: <p>I'm getting this error:</p>
  <blockquote>
  <p>RangeError [EMBED_FIELD_VALUE]: MessageEmbed field values must be
  non-empty strings.</p>
  </blockquote>
  <p>This is my code:</p>
  <pre><code>client.on('ready', () =&gt; {
      console.log('Client | ✅')
  
      command(client, 'ping', (message) =&gt; {
          let x = `${Date.now() - message.createdTimestamp}` + 'ms'
          console.log(x)
          const embedval = x
          const embed = new Discord.MessageEmbed()
              .setTitle(' Pong!')
              .addField(x)
  
          message.channel.send({ embeds: [embed] })
      })
  })
  </code></pre>