What it checks
A file that has content but not a single readable subtitle — every cue has a broken timing line, the text is not in the expected format — cannot be validated or converted: judging it against a profile would only report its emptiness.
How it is measured
After reading, CueNorm checks that at least one subtitle was read. When none was and the reader reported errors (for example SRT_INVALID_TIMING on every cue), the file is refused. The reader's errors stay in the report, so you can see why each cue was skipped.
When it applies
Always, for every file you validate, convert or import. It is fatal: the file is not processed (exit code 3 on the command line, 422 in the API).
Example
A text file named notes.srt with no valid timing line is reported with one SRT_INVALID_TIMING per block, then No subtitle could be read from this file.
How to fix
- Check the errors listed before this one: they show what the reader could not understand.
- Check that the file is a subtitle file of the expected format, and that its extension matches it.