I just upgraded my Spine editor as 3.8(latest) and tried to click 'New' button on Hierachy tree but I coundn't.
I tried to change Interface Scale but it not helped.
After I turned the Spine into windowed mode(not full screen) and moved the Spine window close to left-up, the New button became available to click. But if I moved the Spine window to right-down, it become unclickable again.
Can you check this and let me know? Please!