You opened a calibration, changed a value, saved it, and the flashing tool now refuses the file. Nothing is broken.
What the number is for
A calibration carries a checksum: a number computed from its own contents. The tooling recomputes it before writing, and if the file no longer matches the number stored in it, the write is refused.
That check exists so a half-transferred or damaged file never reaches a module. It is doing its job.
Why editing trips it
The stored checksum describes the file as it was. Change a byte — one map value, one limit — and the description is out of date. The file is fine; its own summary of itself is not.
What to do about it
Rebuild the checksum so it describes the file you now have.
- The checksum tools on this site do it in a few seconds.
- Files you buy here arrive as read, with the checksum intact — this only comes up once you have edited one yourself.
When it is really a bad file
If a file is refused before you have touched it, that is a different problem: an interrupted download or a bad read. Re-download it and try again before assuming the module is at fault.