Windows 8.1 build 9477 (fbl partner out21)

Windows 8.1 build 9477 (fbl_partner_out21) is an unconfirmed 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. Two photos was found on the Chinese website BetaWorld. It was supposedly uploaded to the aforementioned site on 4 May 2019, but at the moment this cannot be confirmed or refuted as it is not publicly available.