I'm using Mojave and I'm trying to change the permissions for this file
/System/Library/PrivateFrameworks/Slideshows.framework/Versions/A/Resources/Content/EffectDescriptions.plist
I want to alter the duration that slides appear in my screensaver which I've figured out how to do but I cannot save my edits to the file. I continually get the error Operation not permitted. I have tried editing the file on the desktop that moving the file back but that does not work. That operation is denied. I cannot change permissions through getinfo and I cannot change permissions through the terminal command:
sudo chown myname /System/Library/
And also
sudo chown myname /System/Library/PrivateFrameworks/Slideshows.framework/Versions/A/Resources/Content/EffectDescriptions.plist
This article seems to deal with the problem but I really cannot tell what the guy is saying:
