For the option of TeX programs in the preference of TeX Live Utility, I have read that the path /Library/TeX/texbin should be applied. However, when this path is used in TeX Live Utility, I got the following message: The tlmgr tool does not exist at /Library/TeX/texbin/tlmgr. Please set the correct location in preferences or install TeX Live.
The only thing I can do now is to set the preference of TeX Live Utility with the path of the local folder (x86-64) to normally update the packages.
So where went wrong in this case?