Wanting to see how my VL.CoreLib.vl looked, I opened it (And could not see anything).
When I used CTRL+W to close the patch, I got this.
I guess I can just use the keyboard shortcut to click the no button, but I think adding a list that is shorter than the screen is tall and a scroll bar might be a good idea.
Confirmed, this is awkwards. But anyway you never want to close the VL.CoreLib. Instead, to get rid of an open VL.CoreLib tab simply hit it with the middle mouse button, to hide the tab.