In a project ,I have a group track set up as a pre master bus (Bus 1) I have routed all instrument tracks to Bus 1 to use as a reference for waves vocal rider.The mono vocal track, is routed to the Lead Vox group channel. In the last insert, I have inserted waves vocal rider, turned on side chain, then tried to route the side chain send to Bus 1, but there is no Bus 1 option, thought maybe it was a routing problem, but realized that I have the
Lead Vox Group channel routed to the Main Stereo Out. Is this a bug? 
Bump
Ehmm, you don’t route Vocal Rider side chain to bus 1, you route a send from bus 1 to the Vocal Rider plugin.
Or maybe i don’t understand what you are trying to accomplish?