Hate to bring this back up but I'm at wits end trying to get SU18 to work with my SM. I've tried copying the files as suggested and upgraded the driver today to 10.5, which 3DC claims to support SU18. I'm now getting following error msg when starting SU18. Any suggestions greatly appreciated.

Error Loading File C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp/3DxSketchUpExt.rb
Error: #<NoMethodError: undefined method AttachSkpExtension' for TDx:Module> C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp/3DxSketchUpExt.rb:24:in module:TDx'
C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp/3DxSketchUpExt.rb:10:in <top (required)>' C:/Program Files/SketchUp/SketchUp 2018/Tools/extensions.rb:197:in require'
C:/Program Files/SketchUp/SketchUp 2018/Tools/extensions.rb:197:in load' C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp.rb:22:in register_extension'
C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp.rb:22:in <module:TDx>' C:/Users/Sam/AppData/Roaming/SketchUp/SketchUp 2018/SketchUp/Plugins/3DxSketchUp.rb:11:in <top (required)>'