I'm using Reaper 5 and Reason 10.4b4. After Pigments 1.2 I update I am having the same problem loading Pigments, Wave Lab 4, CMI V and Mellotron. GUIs won't build. Tried reinstalling Pigments and all of V 7 both manually and using Arturia Software Center, and still have the same problem. Sent a ticket in to Tech Support, so hopefully I'll hear something soon. Will try the VST3 versions and standalone modes to see if that works.