A camera can't update the firmware

[Sunar]

We have a camera with the version 21.1.0.40. It shows an available update (version 21.1.0.99). When I start update everything seems ok, but in the end of update instead of resultCode = 65 it returns result code = 56 and the firmware of camera isn't updated. On the second camera with version 21.1.0.95 the firmware updated successfully and returned resultCode = 65. How to update the first camera?