Also this link shared a user's experience about how he found a workaround. He Turned off his iMac, changed his mouse for an Apple one then turned his iMac back on. The option became available, thus he checked it and changed the mouse again.
Also this link shared a user's experience about how he found a workaround. He Turned off his iMac, changed his mouse for an Apple one then turned his iMac back on. The option became available, thus he checked it and changed the mouse again.