Chroma key not working

[Fa38]

My chroma key effect isn´t working properly, I´ve used this tool multiple times before the update and worked just fine. Whenever I try to select the key color, it doesn´t do anything. I´ve tried with the videos I edited before and it´s the same thing. Please help!

[Peru Bob]

Try pressing Enter to render the timeline and turn the red line above the timeline to green.