Storyboard procudes weird white box in the corner

I'm trying to use the Storyboard together with timeline to produce some fade to black transitions.
But I get this whitebox in the bottom-left corner when I use it (other than that the fade to black plays nicely):





This are the setting of the Storyboard extension:



I have tried to play with the Render Mode and the sorting order but no avail.

Any idea what could be causing this? Is there any other way easy way to achieve this with cinemachine?

Thanks!

 

The project is quite big at the moment, let's see if I can isolate it.

If I have to guess and I would say is some sort of incompatibility between Unity UI Canvas (since I guess you use that internally) and NGUI.


Either way, I wanted to say that, every now and then I ask some questions in the Unity forums and cinemachine is one of the only few that I consistently get, at least, a reply. So many thanks for always being available!

 

We have the same issue. You can see it here in the demo cinematic.

 

Just saw that the cinematic is not on the page anymore, sorry for that. Here at 4:06, it is visible in the bottom-left corner:

Will try to set up a repro project once we'll find a free hour.

 

The quad object is named "Viewport" and is not accessible in the Project Hierarchy (maybe HideFlags.HideInHierarchy?). Here's a screenshot from within the editor.

 

I'm on Unity 2021.3.0f1 and CM 2.8.4