I already solved the problem, the file /boot/config/secrets.tdb was corrupted. First I took the flash memory unraid server and I went into windows, when I detected that the file was corrupted did a "CHKDSK / F" to the unit. I downloaded the unraid version of the website. I put it in the folder windows config and install the original config folder. I uploaded the flash memory on the server and when you turned the power off. File generated secrets.tdb I save it to windows. I deleted the config folder and installed the previously saved config folder, I deleted the config file / secrets.tdb and copy the file secrets.tdb saved earlier. when I went back inside the flash memory on the server everything worked properly.
You think I could avoid such errors in the files, installing ECC RAM?