There is a fail safe built into the HDX where if the system detects a corrupted configuration file it will reboot it self to attempt to correct the problem. If after 3 reboots it cannot correct the problem it will erase the config files and return to the factory out of box defaults.
The latest versions of software have code that will limit the reasons for the corruption but still cannot prevent it.
If more that one system went down at the same time there was probably a power failure or spike.
Be sure that all systems are on adequate surge protectors. Also it is a good idea to keep a backup copy of the config on a laptop or PC somewhere.
The profile can be backed up using the HDX WebUI Utilities section Profile Center.