Fusion Viewers not working in v20 b3

Since v20 beta 2, any Fusion work that I had already done now doesn't show in the viewers. It doesn't matter which nodes I attempt to preview, media in, media out, anything in between, they don't show in the preview windows (Clean feed and normal preview window).
However, anything that doesn't have any fusion composition shows.
Would anyone have any ideas what's wrong ? It used to work prior to v20 beta 2.
However, anything that doesn't have any fusion composition shows.
Would anyone have any ideas what's wrong ? It used to work prior to v20 beta 2.