User lacks the specific role required by an ACL, UI action, or application module after recent role changes or new application installations. (high likelihood)
Role names were modified during a system upgrade or plugin update, breaking existing references in ACLs or scripted conditions. (high likelihood)
Custom application or scoped application references a role that was deleted or renamed without updating dependent configurations. (medium likelihood)
Role inheritance chain was broken due to changes in role hierarchy or contains_roles relationships in the sys_user_role table. (medium likelihood)
Hard-coded role names in business rules, client scripts, or ACL scripts reference non-existent roles due to typos or outdated references. (low likelihood)