Deleting an early index in the targeting options set produces php error upon start

Steps to reproduce:
Create personalization.

1. Add block variation set, which has a two variations.
2. Then add element variation set, which has one default control variation and two other variations.
3. Delete the element variation set's default control variation.
4. Try to start with personalization.
5. Personalization will not start: Undefined offset 0 in acquia_lift_implement_targeting (line 1247 of acquia_lift.admin.inc)