I noticed this in the first Stoke beta too but forgot all about it. When you create a PRT Loader based on a Stoke sim, then try to launch the Particle Data Viewer (and hit update), you get a beep error and it leads me to this line inside Krakatoa_ParticleDataViewer.ms:
for f in ParticleSourcesList[ddl_sources.selection].fileList do
(
for i in FranticParticles.GetFileParticleChannels f where findItem allFileChannels i[1] == 0 do append allFileChannels i[1]
)
Tobbe