If you try to pair a Bluetooth remote that was previously already paired with the same Mac (f.ex. after wiping and reinstalling the operating system), macOS sometimes fails to pair with the remote.
Our theory is that the Bluetooth remote already has stored a link key for the Mac and tries to re-use it when the Mac attempts to re-pair with the remote. But since the Mac no longer knows about the link key and tries to use a different one, the pairing fails.
Fortunately, most Bluetooth remotes affected by this issue store only a single link key. Pairing the remote with another device then will overwrite the existing link key that we believe is causing re-pairing to fail with the Mac.
So if re-pairing a remote with your Mac just doesn't finish and you have an iPhone or iPad, too, try the following steps:
Open Bluetooth settings on your device
Open the Settings app on your device and select "Bluetooth".
Follow the pairing instructions
Follow the pairing instructions displayed in Remote Buddy 2 for the remote to enter the remote's pairing mode.
Pair the remote with your device
When the remote is shown in your device's Bluetooth settings, tap its name and confirm that you want to pair it with your device.
Turn off Bluetooth on your device
Temporarily turn off Bluetooth on your device, so the Bluetooth remote can't re-connect to it.
Retry pairing the remote with your Mac
Now retry pairing the remote with your Mac, again following the instructions displayed in Remote Buddy 2 for the remote.
Once pairing with your Mac has succeeded, you can turn Bluetooth on your device back on.