Trying to set the "updater" preference in Adobe Acrobat on Mac behaves as follows:
- it seems to be on by default
- one can try to turn it off. This step calls for an admin password.
- assuming one gives a correct admin password, the pop-up window closes and it appears that the preference has been changed
- opening the preference panel again shows that the preference has not been changed; "automatically install updates" is still on

This error is occurring with both Acrobat Pro DC 2018 and Acrobat Pro 2017. Base O/S is MacOSX 10.12. O/S and Acrobat are at latest patch levels.