Yeah, I'm having the same problem... last night, my controllers where pairing just fine. But now, it'll go through the process of pairing, but then will say failed to connect, and the Wiimote just keeps blinking blue. Is there something I should reinstall? I've tried restarting my computer and also trying my Wii U Pro Controller, but nothing works.
Okay, so I got it, I have no clue if this will be consistent, but all I had to do was to an actual restart to the computer (instead of putting the computer into hibernate, which is what I actually did). I opened WiinUPro and tried connecting and started working almost immediately.