HALion Sonic LIBRARY NOT FOUND PLEASE HELP

HI there

I bought Cubase Elements 8 a week ago and love it. I have also been enjoying Halion Sonic SE. but today for some reason Halion Sonic will not load up any sounds. It seems like it cannot find the library. Groove Agent is having the same problem. They both worked fine for a few days so the library must have been installed.

Can anyone please tell me how to fix this? I have uninstalled and re installed Halion Sonic and the library from the disk but still the problem remains.

Do I need to re install the whole of Cubase to fix this?

Please help

Many thanks