What you have with regards to VST folders and scans looks correct to me. You may have installed 32 bit when you needed 64 bit. I do not have a solution, but if this was happening on my machine:
- Uninstall the Arturia (VST3, 2, AAX, 32, 64 - All Flavors)
- Reinstall the Arturia VST2-64 and the stand alone instruments (I’m still wary of VST3)
- Make sure the Stand alone Arturia instruments work
- Start up Cantabile and see what happens