Workstation 12 is supposed to be "high DPI ready" but that doesn't seem to be the case. The scaling in guest OS's is ok but there is a problem on the host machine. I have a laptop with a 4k display and have it connected to an external 27" 2k display when I'm at my desk. The 2k display is my main monitor which is required for GSync to work on it.
Based on Microsofts information for developers on display scaling (Display Scaling changes for the Windows 10 Anniversary Update | Ask the Core Team) the app seems to take the information about the Main display without taking into account which screen it is actually on. It sounds like for a fix you simply have to reflow the UI depending on which screen the app is actually on.
Photo of the issue
Basically you cant see the VMware UI on the larger screen because it is using the Main screen's resolution and scaling settings while it is on the secondary display.
