Organic Groups exposed filter error "An illegal choice has been detected. Please contact the site administrator." and choice defaults to an item, not ANY
Case: Drupal 7 installed, with Organic Groups 7.x setup. In Views, added an exposed filter for a particular field (that will filter from a Content Type that is set up as both a Group and a Group content in OG).
Exposed filter setup: Single filter, NOT required, Select all, NOT limited to selected items