After updating the OS to Catalina 10.15, I can no longer open Suitcase Fusion 6 (ver 15.x.x) or earlier
This issue occurs on Mac OS X 10.15 using Suitcase Fusion version 15.x.x or earlier. 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. Any 32-bit applications still present after the update became inaccessible and marked with a symbol
You will need to purchase an upgrade to Suitcase Fusion version 20.0.7. You can see upgrade pricing and information here.