I am using Lightroom 4 and it recently stopped launching, I am using OS 10.13.2 on a Mac book pro. Any help
Lightroom 4 will not run properly (if at all) under OS 10.13.2.
You need to upgrade (purchase) to Lightroom 6.14 or subscribe to Lightroom Classic CC. Or you can downgrade your MAC OS to Sierra (not High Sierra).
Retrieving data ...