Enable Improved Caching of Org Schema
Where: This change applies to Lightning Experience and Salesforce Classic in Enterprise, Performance, Unlimited, and Developer editions.
Why: This critical update fixes known bugs by improving internal systems that define and cache org schema, including standard objects, custom objects, and their fields. The documented behavior of your org’s schema remains unchanged. The update fixes bugs where the documentation doesn’t match the known behavior. This update also resolves rare, intermittent cases where undocumented object types are visible in Apex describe result methods or where version-specific schema details could be improperly reused.
How: From Setup, in the Quick Find box, enter Critical Updates. To learn more about the update, click Review. To activate the update, click Activate.