Passes the scan in the plug-in manager, but when I try to use it I get the message that the plug-in may not have installed correctly. Tried deleting the vst files and re-installing, but that didn't help.

there isn't a 64 bit version of the plugin (from what I see anyway) .  pretty sure it's DirectX also, as I'd like to use it elsewhere but can't 

just tested it here in 64 bit ,works (bit bridged).. perhaps the problem is your rex/rx2 library version.

have a look in C:\Program Files\Cakewalk\Vstplugins\RXP

right click on "REX Shared Library.dll" see if thats version 1.5.4

how do you get on with "dropzone" also , if you drop it an rex/rx2?

>there isn't a 64 bit version of the plugin (from what I see anyway) I have an RXP.dll in C:\Program Files\Cakewalk\Vstplugins\RXP\. Why wouldn't that be 64 bit? Yes, the shared library is 1.5.4.

because it runs bitbridge as a wrapper = not 64 bit

could someone help to upload to me the TTS-1 32 bit and RXP  DXi vst plugins, need it urgently
thank you

In order to get those plug-ins installed correctly requires running the SONAR installer. Try running your SONAR installer which included those plug-ins using the advanced option, then select those two plug-ins when prompted for what parts of SONAR to install.