Lumetri Match Not Working

[Chummystyle]

Hi everyone,
This problem has occurred out of nowhere today, mid project editing.
I apply the effect but the Match option is greyed out. Everything else works in the effect.
I have tried different footage, a still / image from the video and the effect, rebooting, resetting preferences and a new project with the old one imprted and still no Match option.
Any ideas guys?
Chummy 

[Chummystyle]

I've gone back to an older version and it's working now.