Universal Containers, a global corporation of 50,000 users, has a 24x7 call center operated by 20,000 users that includes employees and contractors. Their sales organization is 10,000 strong and they started processing about 100,000 updates to opportunity custom fields called Priority and NextStep. They also started processing 20,000 updates to a highly nested territory hierarchy. There was a third mass update on a Next Step field on the Action Plan custom object that has Case as a lookup field. Users started seeing a Group membership lock error in the system. What is a probable cause for this error?