Message Oracle ORA-38856 - cannot mark instance string (redo thread string) as enabled

ERRORcannot mark instance string (redo thread string) as enabled
CAUSEThe open resetlogs or standby activation operation failed because it needs to mark an instance (redo thread) as enabled. However, it had less than 2 online redo logs, which prevented it from being enabled.
ACTIONAdd more logfiles to the specified instance and retry the command.