caffeine won't start

Hello,
caffeine doesn’t appear , in a terminal

** (caffeine:22817): WARNING **: Couldn't register with accessibility  bus: Did not receive a reply. Possible causes include: the remote  application did not send a reply, the message bus security policy  blocked the reply, the reply timeout expired, or the network connection  was broken.

If anyone have an idea for this bug ? thanks
Leap + mate 1.14