For the moment Metaspolitable 3 works with Virtual Box not VMware. This is what I found looking on rapid7 website (Developer of Metaspolitable3)
Keep in mind, instead of downloading a VM like before, Metasploitable3 requires you to issue a few commands and build for Virtual Box (VMWare will be supported in the future soon). To do so, your machine must install the following requirements:
https://www.rapid7.com/blog/post/2016/11/15/test-your-might-with-the-shiny-new-metasploitable3/
