@cgm2016 you can uninstall by quitting f.lux (in the menu to the left of your system clock) and deleting the files. You may want to check if your MBP is one of the ones affected by a video driver problem, this isn't normal behavior with f.lux: www.macrumors.com/2015/02/19/2011-macbook-pro-repair-program-apple/