So I got in trouble for giving a Lecture on Racism in America

I’m an 8th grade English language arts teacher in the suburban areas, my school is dominantly white. I recently taught a unit on to kill a mockingbird, and I gave my students a lecture on how racism has changed, I gave the examples of it being more covert than overt and how the subtle racism is (micro aggressions) and I showed my students a video on micro aggressions so they could understand. The day after I gave the lecture I got a call from my vice principal saying I got a parent complaining about the lecture, and asking if I could do anything about it. At the time I was like it’s probably just some misunderstanding so I gave the vice principal the PowerPoint presentation I gave to my students. The vice principal called me back and said I have to take down the video, my principal called me and said I should take down the lecture. I didn’t argue but I find it very weird that I got in trouble for giving a lecture about micro aggressions/racism, I’m just really confused and I would like to know your thoughts on this situation.<br><br>Edit: For clarity it was a 2 hour lecture that I broke down into two parts over the course of 2 days, I gave them 1 hour and 15 minutes of lecture the first day and 45 minutes of lecture the second day, the 45 minutes were video examples of micro aggressions , I also let the students have a discussion the second day about racism and gave them the opportunity to ask questions without fear of being judged.