Windows 10X build 19540

Windows 10X build 19540 is an unleaked build of Windows 10X. It was mentioned along with builds 19531 and 19561 in a screenshot shown in the article "Use the Microsoft Emulator" posted by a Microsoft employee on Microsoft Doc on 2 June 2020. Judging by the dates provided, it could have been compiled on or before 6 December 2019.