I don't remember specifically how I fixed it on my Note 3 but now I can't fix it on my S6. In the advanced settings, deny phone setting access is checked. I forgot to uninstall anti-theft and I did an downgrade-upgrade. I tried installing the Play Store Version, that installed. Couldn't install the root version because Unknown sources needs to be enabled in settings (which I can't access, that's why I'm making the post). Tried doing the removal wizard. In Hard Reset protection I can't select either one.
To summarize, I can't access settings. Everytime I try to get into settings it'll show "Unfortunately, Settings has stopped" and that's because I didn't uninstall avast! anti-theft before restoring my phone. Please email me. I need to fix it immediately