When you download RPR for Blender for macOS from the website and install it the 2nd installer dialog is blank.
The first dialog after beginning the installer is this:

The second dialog is this... I don't know what to press.

This has been in every v1.7 installer for macOS and is still in the latest Mojave RPR 1.7.217 installer.
Mac setup:

This bug was happening in High Sierra 10.13.6 as well.