Another bug:

The properties menu when editing containers is wrong if you: edit container A and hide that menu. Go to container B and show that menu. Properties of the container A will be shown. (It is not necessary to use desktops)

This can make also a bug: if that previous container is a deleted one, I tested with a desktop, it will undo the deletion when editing a propertie, or crash. (Note to Pierre Hébert​​: this is what I did in the email I sent to you)

Now I’m thinking this is expected (if you are undo a panel deletion for example it needs to go back) the problem is, I think, when the panel is deleted somehow and can’t be restored.