Broken note input?

Hi, everyone. I just bought Dorico and am fiddling around with some of the features.

I’m not sure why, but every time I add a player mid-composition, Dorico no longer lets me input notes with my mouse. I can click on a measure, and occasionally input pitches with my keyboard, but I can’t control what the duration is, nor does the little note head pop up on my cursor anymore. Can you help? I’m totally at a loss.

Welcome to the forum, Person9999. Have you perhaps activated the “selection tool”, the pointer arrow at the very top of the note input toolbox on the left-hand side of the screen in Write mode? When that is active, mouse input is disabled.

if you hit enter on your keyboard you will go into write mode