My hard drive crashed and I have tried repeatedly to activate Silver Effects but no matter what # I use, those shown and one in my records, they are shown as invalid.
I remember that the serial number you have in your account need to be given when you install NIK Collection (setup procedure).
If you try to activate a plugin later it will not work.
You might need to deinstall NIK to be able to restart the procedure.
Hope this helps…
You can just re-install instead of de-installing and installing again. When you install it, it override the last.