I have literally just gone through the intro to Flash on Lynda.com (Up and Running) and I just opened a new project--nothing more. And my stroke commands are frozen. I am used to the red line from PS but in my experience you just click on it and get the color selector and deselect the red bar. Nothing seems to help here. You'll see I could select yellow, per instructions, on the icon, but nothing changed in the Fill and Stroke panel, and I can't change anything there.
Granted, the movie is from 2013, so maybe there is some step introduced in the last three years.
I just checked, and it is working for me. Can you try resetting preferences? Re-create preferences
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