The DXi plug-in stopped working - howcome?

Roland Virtual Sound Canvas DXi

I’m using build 2099 of Ntrack 4.
I have some songs that have both midi and wav files. I set them up in Ntrack and everything appeared to work fine.
Yesterday when I opened the files I got an Ntrack error message: " Error loading Plugin: Virtual Sound Canvas DXi" When I closoe that message I get DirectX Error, "Failed connecting DriectX plug-in Pins."
The (Synth) track is now listed as a group. I uninstalled the Roland Sound Canvas DXi and reinstalled and the program worked as it should. This morning when I opened the song I have the same problem and errors as before.
The DXi is listed as an available plug-in in the DirectX Ntrack dialogue box and Band in a Box 2006 and PowerTracks 10 both find it with no trouble.
Any ideas on what is happening?