VST only works in Cubase 7 if added in older version

Cubase
1

Hello,

I’ve an odd issue. If I add CynthiaFX as an insert in Cubase 4 and then open that in Cubase 7.5 the VST insert works, but if I add CynthiaFX as an insert in Cubase 7.5 it silences the track. Very odd. This is in both 32 and 64 bit.

Any suggestions why?

Thanks,

Dazzer