Welcome to the OptoForums! The part number you mention, the SNAP-PAC-EB2, is a brain (vs. a controller). You'll need to download your "strategy" (the logic you're writing in PAC Control basic) to a controller, which will then connect to the brain. You'll configure the -EB2 in your strategy tree under "I/O Units" (vs. "Control Engines").
The control engine can be: a SNAP-PAC-S series (controller only), SNAP-PAC-R series (both controller & brain), or SoftPAC (software controller that runs on a Windows PC). There's also the free demo/trial subset of SoftPAC called "PAC Sim" which can also run on your Windows PC and talk to the -EB2).
Check out this Controller/Brain comparison doc here.
This confusion between brain vs. controller happens a lot. If I've misunderstood where/when you're seeing this error (I'm guessing it's when you go to try to download/debug the strategy?) then let us know more details, and we'll get you sorted out.