RDS 5.4.1 (released April 2020) is often required for legacy compatibility:

Hexagon RDS 5.4.1 Download: Essential Guide for Metrology Professionals

: This version is specifically optimized for RA7 and RA8 Absolute Arms and is required for SpatialAnalyzer versions 2018.02.16 through 2021.1.

: If you are using Windows 7 , you cannot update to any version newer than RDS 5.4.1.