In Ubuntu 18.04 with Unity 7.5.0 I have to use the solution provided by Michael (see #7 - https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1292833/comments/7).
In Ubuntu 18.04 with Unity 7.5.0 I have to use the solution provided by Michael (see #7 - https:/ /bugs.launchpad .net/ubuntu/ +source/ unity/+ bug/1292833/ comments/ 7).