Vst sound sets won't load

I’m using Cubase 7 and am getting problems with both loading Vst instruments and loading Vst sound sets into Halion sonic se.

I open the Vst instrument rack, navigate the menu to select the instrument in this case Halion 5 but nothing happens it doesn’t appear in the rack. Same effect with Halion Sonic 2.

Halion Sonic SE does however load, but that’s when I find the second problem that any vst sound set I select just hangs on loading. I see the load progress bar in HSSE move to about 50% then it just hangs and I have to cancel the load to continue.

Anyone with any ideas on this, I’d guess it may be some sort of path problem for both errors but I have no idea where to look. Are both Hal5 and HS2 Vst 3 instruments and therefore have to be installed in specific directories?
Where should the vast sound files reside for the Vst instrument HSSE 2?

Help please.

Cheers
David

Having played around with a few settings, it appears the answer to this was linked to the multicore settings of the virtual instrument. The default setting was off. Setting it to the max 4 cores for my CPU everything seems now to run OK. There is warning message which indicates if the DAW (Cubase 7.5) and the VSTi are both using multi core that dropouts could occur. I haven’t noticed this occurring on my iMac i5 processor (8gb ram).

If you are having loading VSTi this setting could be worth a look.

If any other users have observations on the multicore settings and ram/disk setting Id be interested in any feedback.

Cheers
David