I can confirm, the bug is still present on unity-control-center (15.04.0+16.04.20160315-0ubuntu1).
Tested with 1byone keyboard (both bluetooth 2.1 and 4.0 adapters) and also with a Microsoft Wedge Keyboard (just when using a bluetooth 2.1 adapter)
If I put the PIN Code show in the btmon output the pairing process is successful and the device is working.
btmon log attached.
I can confirm, the bug is still present on unity-control- center (15.04. 0+16.04. 20160315- 0ubuntu1) .
Tested with 1byone keyboard (both bluetooth 2.1 and 4.0 adapters) and also with a Microsoft Wedge Keyboard (just when using a bluetooth 2.1 adapter)
If I put the PIN Code show in the btmon output the pairing process is successful and the device is working.
btmon log attached.