I had just updated to Catalina, was still working. My laptop auto updated to Big sur 11.4 and now I can't adjust screen brightness same problem, MacBook Pro Retina, 15-inch, Late 2013.
mcph26
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I had just updated to Catalina, was still working. My laptop auto updated to Big sur 11.4 same problem MacBook Pro Retina, 15-inch, Late 2013