I've just come across an issue - When I select Clip / Target and choose active layer - it stays on the default of 'Composition determined' no matter how many times I choose another option.
When I set it via the composition setting though it works as expected (like old Resolume v2).
This happens in older versions of Arena I've tested so I assume it's connected to the newest OS-X Update or has been a bug not spotted before.
Arena 4.2.1 w/ 10.10.4 setting Clip / Target not working
Re: Arena 4.2.1 w/ 10.10.4 setting Clip / Target not working
Hmmmm. Just done a quick test and works for me. Maybe you could post a screenrecord of this happening or contact us directly so we can set up a Teamviewer session?