It is the first thing you need to fix the issue as stated above. For that, you need to run the virtual machine showing the error and go to the Devices > Install Guest ...

Virtual machines can seem juuuuust a bit too geeky for most otherwise computer-friendly people. That's sad, because it's an easy, free way to try another operating system, or use those one or two apps ...

As a person who uses Linux regularly, often I am asked about my opinions about other operating systems, especially those coming from large companies located in Redmond, Washington. Here's the deal.