assertion.bmffHash.mismatch
The BMFF boxes do not match the signed box-hash assertion.
Failure code
What to do
The media container was edited after signing. Re-acquire the original signed file before relying on it.
Verify it yourself
Install the open-source Encypher C2PA CLI and check any file. It runs locally and reports these status codes.
cargo install encypher-c2pa-cli
Build verification into your product
The Encypher API returns these status codes over HTTP. Read the reference to wire provenance checks into your own workflow.