Windows 8.1 build 9477 (fbl partner out21)

Windows 8.1 build 9477 (fbl_partner_out21) is a build of Windows 8.1. This build is a later compile of build 9477. It is known that this build exists only in the ARM architecture. One screenshot was found on the Chinese website BetaWorld. It was supposedly leaked to the aforementioned site on 4 May 2019, but at the moment this cannot be confirmed or refuted as it is not publicly available. As of 2021, it remains unleaked.