Steps:

1. Create Landing Page with Collection block, link content and publish
2. Remove linked content
3. Go to edit mode of Landing Page from step 1
4.Click settings button from Collection block

http://g.recordit.co/VtmV7Omgup.gif

Actual result:

Block disappears, but if you drag and drop another block it is displayed again.

Expected result:

Settings modal is displayed.