Hi,
the Message "Embedded Flash/SD-CARD" is not the SD-Card, it is corrupted NAND memory from the iLO.
So Update the iLO to the latest version and follow the iLO NAND Format, as Thorsten posted:
https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-a00048622en_us
But the Server reset, may not come from this message.
It can also be a Power Supply problem or a Hung OS.
You can disable the ASR Feature, to see if it is an OS Hung problem.
https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c01158873