Thank you everyone for your replies.
I'm using VST3 (always used VST3, never had a problem before), Reaper (not Reason) is x64 version. I try it with a new created project, I add a new track, add FX, select Helix, boom!
When I try to load the plug-in as a separate process it fails to load, in this case Reaper remains fine. I am missing something, probably something simple but can not pin point it somehow...