Turn off Ctrl + F5 to close?

I need to put a lot of footnotes in my Scrivener document and the shortcut for this is Shift + F5, however I’m occasionally pressing Ctrl + F5 by mistake which closes the window. I never have to use this shortcut on purpose so it’s quite irritating, is there any way to turn that off?

Go into Options->Keyboard, find the File section, find Close All Projects in the File section; It should show Ctrl+F5 as the assigned default keystroke. Click that row, then look at the far right of the “Key Sequence” edit control where there is an “X” in a circle. Click that “X” to unassign the keystroke.