I've noticed on the newest version of Acrobat DC on Mac you cannot see where rules are going to land on the document until you un-click them. In the past when you pulled out a rule there was a corresponding line on the ruler and usually some sort of a preview of the rule. Is there a way to turn that back on? It is difficult to layout precise rules without seeing the preview.
As per the issue description mentioned above, rulers lines are not visible during dragging, is that correct?
Could you check if an update is pending for Acrobat using "check for updates" option under Help menu, rebooting the machine and check if that helps. You may also download the updates from this link: Adobe - Acrobat : For Macintosh
Also, let us know the dot version of Acrobat installed on the machine? You may refer to the steps given in this link for the same: Identify the product and its version for Acrobat and Reader DC
Let us know if you need any help.
Acrobat dc version 2015.006.30280
Thanks. Could you try installing the latest patch for Acrobat using this link: 15.006.30418 Planned update, May 14, 2018 — Release Notes for Acrobat DC Products , rebooting the machine and check.