I had the same trouble on my Macbook Pro runing 10.9.5 - wouldn’t recognize any of the three Wiimotes I’ve tried. Finally, I thought of seeing if the Mac would recognize the Wiimote at all as a bluetooth device. With Wiimote Whiteboard still open, I opened Bluetooth Preferences and it started searching for devices. As soon as my Mac found the Wiimote and recognized what it was, it popped up in Wiimote Whiteboard as it should have in the first place. I never connected through Bluetooth Preferences on the Mac, just through WW. I believe I’ve had to do this each time I’ve tried to use WW, but it’s worked fine after going through this process.