The Official Reality forums

It seems that those particular presets are empty on mine as well

Try the following, Delete the Mesh Light, Close Reality, The press CMD+Z to undo the delete, Re-Launch Reality

Try setting the Negative & Positive to 0.0003, Select Use Micro-Facets & set the SubD to 200 as a starting point

Its been reported that DIM (DAZ Install Manager) doesn't work on MacOS X Mojave, Tho I believe they are working on a fix (check DAZ forums for more info). As for Reality/Lux I can't say as my Mac is to old for the latest OS Update.

I have a complete tutorial on getting started with Reality here

viewtopic.php?f=23&t=643

Thing to check and try 1. Make sure that you don't have an old version of Reality installed (Installing a newer version of Reality while an old version is installed has been known to cause problems) 2. Completely remove Reality, Download a fresh copy, reboot and install 3. Make sure that both Realit...

That particular product is using iRay's version of Reality's Volumetric Settings and a such have been designed to work only in iRay. To do the same thing in Reality/Luxrender you would need to recreate it using Reality's Materials & a DAZ Studio primitive (like a cube) to contain your atmospheri...

Check to make sure that you have the folders set correctly under DAZ Studio Prefs - Content Manager

I can safely say that DAZ + Reality work fine on MacOS X High Sierra (10.13.5), Either your installation of Reality or DAZ Studio has got corrupted some how. To completely remove Reality you need to delete the following folders - Applications/Reality Applications/DAZ 3D/DAZStudio4 64-bit/Plugins/Rea...

You can also try this, Close REALITY, select the object that you are having problems with in the Scene Tab, Now hit Delete, then Undo the delete either from the Edit Menu, or using the Keyboard Shortcut, Now start REALITY and the obj should appear.