Symptom: the file exists and appears well-formed, but the application does not load it.
Recognition is a separate step from parsing. A tool can decline to treat a file as a keyset before examining its contents, which is why this case is distinct from a format problem.
Likely causes
- Filename expectation. The application matches an exact name and never looks inside a differently named file.
- Wrong directory. The file is valid but not where the application searches.
- Multiple copies. An older copy in a default location takes precedence over the intended file.
- Permissions. The application cannot read the file, and reports the outcome as a recognition failure.
How to confirm
Establish the exact expected path and filename from the application’s documentation, then confirm which file is actually present there. If more than one copy exists, the effective one may not be the one you edited.
Where this connects
The environment end of the compatibility chain is explained in emulator & frontend configuration and keyset-aware desktop tools. If the tool reports no file at all, see missing keyset.