Cannot find HALionOne instruments on MacBook Pro

I’ve recently changed my platform from PC to MAC and have installed Cubase 6.5 and my current files on my MacBook Pro. Basically all has gone well but I’m experiencing the following problem.
If I open an already existing project that contains HALionOne instruments it plays just fine, but if I try to edit a HALionOne track or add a new one I cannot find any instruments. The same occurs if I create a new project . . I cannot find any instruments within HALionOne.
Can anybody give me some advice on this one . . .
Many thanks . . . Martin