LookupPrivelegeValueW(0, SE_BACKUP_NAME...) failed with error: A specified privilege does not exist.

[Dalebjörk, Tomas]

Hi,
We have encountered an error from the EnableBackupRestorePrivileges() function.
The error is from the LookupPrivelegeValueW() function.
The operating system error is: "A specified privelege does not exist."
This function has been working for several months, it just started today,
We use
union {
    TOKEN_PRIVILEGES P;
    UINT8 B[sizeof(TOKEN_PRIVILEGES) + sizeof(LUID_AND_ATTRIBUTES)];
} Privileges;
Privileges.P.PrivilegeCount = 2;
Privileges.P.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
Privileges.P.Privileges[1].Attributes = SE_PRIVILEGE_ENABLED;
if(!LookupPrivilegesValueW(0, SE_BACKUP_NAME, &Privileges.P.Privileges[0].Luid) ||
!LookupPrivilegesValueW(0, SE_BACKUP_NAME, &Privileges.P.Privileges[0].Luid) ) {
    return FspNtSatusFromWin32(GetLastError());
}

Any tips how to resolve this issue?

Regards Tomas