Oh, sorry. I meant the Arturia support.
And I think I misread the OP's Topic because my issue seems to be different, since the Plugins Show up in S1 but cannot be added to the tracks.
I already did all steps you recommeded below and even just deleted all FX plug ins and re-installed them but it didn't help.
All preamps and filters work fine in Ableton and Cubase but refuse to work in S1 4.6.
As I said, I'm relatively sure that they worked before I upgraded to the FX Collection but I'll try with a S1 Version prior to 4.6. Maybe this is indeed a S1 issue.
Thanks for your help anyway! :-)