sudo doesn't work but su does
Hi,
I've enabled root and set a password. I know what the password is, and it works with su root. I am using an administrator account to login with a complex password (that I also know). However, no matter how carefully I enter the password, sudo always fails as follows:
$ su ls
Password:
su: Sorry
I can get around this with su root, but it's risky and I'd rather not. Any help gratefully received.
Thanks
iMac 27" 5K, macOS 10.14