Kenny80

Hi all, This command doesn't like to be saved when entering all information: sudo nano /System/Library/Extensions/AppleGraphicsControl.kext/Contents/PlugIns/AppleGraphicsDevicePolicy.kext/Contents/Info.plist The error message is "operation not permitted" Even tried to remove the file and again the same message appears. The solution for this problem was not given by this tutorial. I'm running O.S High Sierra. According to the following link: I need to run a command: csrutil disable But it seems I cannot enter the Recovery mode using Command + R. A stop sign occurs when trying to enter it. Who is able to assist me? With kind regards, Kenny