Symptom: the file exists and looks correct, but it does not parse.
Format problems are invisible to the eye and fatal to a parser. They are the reason a keyset should never be retyped, reformatted or passed through a word processor.
Likely causes
- Line endings. A file transferred between platforms can gain or lose carriage returns, which some parsers reject.
- Encoding. A file saved with a byte-order mark or an unusual encoding may fail before its content is read.
- Trailing whitespace. Spaces or tabs after a value change the token.
- Blank lines or comments. Tolerated by some tools and rejected by others.
- Case. Names normalised by an editor rather than preserved.
How to confirm
Compare against an untouched original. Because a keyset has no integrity check, structural comparison is the only reliable test — see format validators and the file-structure guide.
The reliable fix
Replace the file with the unmodified original, or regenerate it. Format problems are a symptom of the file having been handled incorrectly, and the same handling will usually produce the same problem again.
Where this connects
If the file parses but a single entry is rejected, that is a different case — see invalid key. If it parses cleanly and is still ignored, see tool cannot recognise keyset.