Use logics to decide what to do next if an action fails. All actions have a Good or Bad outcome which you can attach follow-up actions to in the editor.
If something unpredictable happens you can use BadEnd to catch the error and/or backup data.
If the template doesn't know what to do next, don't force it to continue running. http://zennolab.com/wiki/en:logic#badend
OMG Thx, that was so logical...
Thx Tobbe !
But just an other question : I can make this when 2 actions are not in a same group but not when they are included in the same group like this :