CS6 Design and Web Premium is asking for serial numbers each time I use Acrobat Pro, it accepts the SN, but it doesn't "stick". Did anything change with the licensing platform? Or, is this something that I need to fix on my computer?
Nothing has changed AFAIK, but this is a user-to-user forum so most of us here do not have the power to fix licensing issues or know what may be going on behind the scenes...
Your best bet is probably to contact Adobe directly:
Using the live online chat is usually fastest/easiest.