Engine 4.6.1 Mac OS 10.10.2
Matinee crashes engine when click on close tab button but ONLY if have editor docked as a fullscreen tab AND have another window tabbed (e.g. content browser). I replicated crash multiple times in two different projects. If Matinee is only tab other than main Editor it doesn’t crash engine. There needs to be 3 tabs (like in picture below) for crash to occur (I didn’t test more than 3).