Based on the release notes associated with this version, the update addressed several community-reported issues:
The .rar file contains the update installer and a "PLAZA" folder. Lust.for.Darkness.Update.v20180719.rar
Copy the contents of the "PLAZA" folder from the .rar and paste them into the game's installation directory, overwriting existing files to bypass DRM. Based on the release notes associated with this
Tweaks to enemy detection ranges and patrol patterns to make stealth sequences more fair and less prone to "instant-fail" scenarios. Bug Fixes: Lust.for.Darkness.Update.v20180719.rar