UnsupportedIndexFormatException

A sidecar or registry was written at a format version, section kind or posting encoding this build does not know.

Distinct from CorruptIndexException for the reason UnsupportedBitmapFormatException is distinct from CorruptBitmapException: the bytes are intact, and calling them damaged would send somebody looking for a disk fault. Every id byte in these formats exists so that a denser encoding or a new kind of sidecar is a new number rather than a new version, and a build that predates one has to say so rather than guess at it.