After updating the OS to Catalina 10.15, I can no longer add or activate fonts to Suitcase Fusion 7 (ver 18.x.x) or Suitcase Fusion 8 (ver 19.x.x)
This issue occurs on Mac OS X 10.15 using Suitcase Fusion version 18.x.x or Suitcase Fusion 19.x.x. If you're not sure of what version you're using, please see this article
On July 9th, 2018 Apple announced their plans for the end of life for 32-bit Application Support, effectively starting with Mac OS X Catalina 10.15. While Suitcase Fusion 7 and Suitcase Fusion 8 have 64-bit elements, they are not fully 64-bit compliant applications
You will need to purchase an upgrade to Suitcase Fusion version 20.0.7. You can start that process here.