Hello Ben,
On occasion, when I open Mach the screen doesn't come up but the icon comes up in the taskbar. Then just click on it.
Otherwise, see if they are in your mach3 folder and open one from there. Turn is .lset. Then maybe it will "stick".
Click "View" on the top bar and they should all be in a pop-up window. (you probably know that already)
RC
How do you confirm in ports and pins ?