Windows 10. Was running fine on XP: PCBs manufactured and sold.
Now, on my Windows 10 PC PCB123 Ver 5-3 downloads ok; I run the download and Sunstone\PCB123 PCB123.exe gets created in my Program Files (x86) folder. Windows 10 says 32-bit. Icon appears on desktop. Program icon appears in Start drop-down menu.
Can run as many instances of the program at once as I want. NO WINDOW EVER SHOWS! The instances hang around until I End Task using Task Manager.
I right-clicked the program and chose Windows XP compatibility. No difference.