The container opened and the demuxer parsed no track at all out of it. The file's streams are in formats it does not carry, so their video cannot be reached even though it is there.
The container opened, its tracks listed, and none of them is video. This is the only case where the file itself is what lacks video.
A canvas was offered to an engine loaded in "frames" presentation mode, where the host owns the only canvas.
The decoder cannot decode this source at all: it refused to configure, it errored, or it acknowledged decode requests and never produced a frame. Distinct from BackendCrashed; this one survives every rebuild, so the runtime stops rebuilding and says so. The usual cause is outside the page: another tab holding every hardware decoder session the machine has.
A playback rate outside the forward range the engine supports.
The demuxer refused the file outright: its container is not one this build reads, so no track was ever listed and no decoder was ever asked.