Fusion preview/viewer is blank/black/checkered

Hello,

Anything I do in fusion doesn't display properly, the preview is blank/black or checkered. However when I leave fusion to edit mode anything added within fusion is properly rendered in edit's preview.

Thanks

Bit vague on how you got to this place, a tiny bit more information may help, maybe a screenshot from your edit page etc. Also skill level etc will be helpful, I don't want to teach you to suck eggs if you don't need it.

So first screenshot, your ellipse tool is just the mask, there is no background going into it, so fusion will not render anything.

So background -> Mask Tool (Ellipse) -> Media Out.

The front running background node will define the resolution of the composition.

Give me some more information about your second screenshot please, maybe your render range is a bit odd.