I had the same problem when updating the Waves plug-ins. The issue, in my case was a double-whammy. First, Waves updated the online code versions from 9.0 to 9.2 or something to that effect, and X2 "looks" for version 9.0, which (now) no longer exists. So, you have to go to Preferences, then VST settings and click "Reset all Plugins". This was absolutely detrimental to any sessions I had previously had Waves plug-ins from version 9.0, but you can open the session in another version of X1 or X2 (someone else's, if necessary) and "save" each Waves plug-ins settings; then recall those settings in the new Waves 9.2 plugs after the update made your life a bit more challenging. Hope this helps!!