On my Windows 10x64 host, equipped with 32 GB RAM and virtual memory disabled, I have two VMs set up with 12 GB RAM alloted to each of them (first is Workstation 15 hardware, the second one is Workstation 16 hardware).

When I try to run both of them, I get the following error message when trying to start the second one:

There should be enough free RAM available:

What's causing this error?