I have the feeling I found a bug in SW2018. But maybe it's something else I'm not seeing.
Assembly open in Exploded state
Click a part to get the corresponding step highlighted (This bug only appears when a step is assigned to one part, it does not appear when multiple parts are assigned to a step)
Delete the step
Now the bug comes to play, because Solidworks now asks you if you want to delete the part (if you click No, it asks you next if you want to delete the step and if you click Yes on that message everything is fine)
If you click Yes Solidworks becomes inaccessible. You can't save, close, switch windows of perform other actions other than clicking the parts and rotating them with the mouse. Solidworks has to be force closed by Windows Task Manager to be able to fix this. (And the part is gone)
Did I discover a bug? Or did I miss something?