Undefined array key "target_id"

Problem/Motivation

Edit an activity on /admin/structure/activity
Edit any activity
Hit save
Get the error

Warning: Undefined array key "target_id" in Drupal\activity_creator\ActivityAccessControlHandler->checkAccess() (line 70 of drupal-10.3.x/html/profiles/contrib/social/modules/custom/activity_creator/src/ActivityAccessControlHandler.php)

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes