Cubase 5 Plugins issue


i’ve got a situation and haven’t found a solution anywhere else for my Cubase 5. For instance my FabFilter and Cubase default plugins work great but all others don’t. Cubase recognized them and the interface shows up but no signal goes thru them. I’ve tried throwing the files around but it doesn’t help. But it works on Reaper so I assume it’s a Cubase issue. I also tried free vst plugins as rough rider and it doesn’t work (it does on reaper)