Guest Users Can’t Be Assigned as Owners of Already Existing Records

Before the Summer ’20 release, guest users couldn’t be assigned as owners of newly created records. Starting in Summer ’20, guest users can’t be assigned as owners of records already existing in the org.

Where: This change applies to all orgs with guest user profiles for communities, sites, and Salesforce Sites.

How: This change is enforced in new orgs created after the Summer ’20 release. Check out Opt Out of Guest User Security Policies Before Summer ’20 (Critical Update) for orgs created before the Summer ’20 release.