Steps:

1. Go to Content/Content structure
2. Click Create and select Form
3. Click Create a form
4. Drag and drop for example Single line input
5. Configure input - fill Display label
6. Click form builder back button
7. Click Trash button

Actual result:

Nothing happens

Expected result:

User should be redirected to form edit mode
https://projects.invisionapp.com/d/main#/console/15079154/313691508/preview