In a project already using Vital, the Vital version was updated from 1.0.6 to 1.5.4 - the project continued to play as desired, but it was impossible to “open” the Vital interface via the Reaper means of clicking on the “FX” button to access plugins. This would crash Reaper.
Latest Reaper
Mac OSX 10.13.6
Macbook Pro 2018 (Late)
Rolling back by forcefully installing 1.5.3 Reaper fixed this bug, everything running fine, though 1.5.3 is FAR hotter running than 1.0.6 as it seems to be churning the GPU even when merely interface open and timeline not playing, so no animations occurring.
GPU is 560X, forced to run (ie not using the Intel GPU)