QL> /
CREATE TABLE PROD.AOS_AUDIT
*
ERROR at line 1:
ORA-43856: Unsupported LOB type for SECUREFILE LOB operation

Couldn't figure out why because even oracle suggested to create table in such a way and the error reports this:

ORA-43856:	Unsupported object type for SECUREFILE LOB operation
Cause:	A SECUREFILE Lob operation was issued on an unsupported object type.
Action:	Don"t use this function for BASICFILE LOBs.

My create table statement:

CREATE TABLE PROD.AOS_AUDIT
   (    NO NUMBER(38,0) NOT NULL ENABLE,
        LOGD VARCHAR2(255 CHAR) NOT NULL ENABLE,
        REPLAY VARCHAR2(4000),
        AUDITMSG CLOB,
        REPLAYTIMESTAMP TIMESTAMP (9),
        DBTIMESTAMP TIMESTAMP (9),
         CONSTRAINT SOAAUDIT_PK PRIMARY KEY (NO)
  USING INDEX
  TABLESPACE AOS_IDX_TBS  ENABLE
   )
  TABLESPACE AOS_DATA_TBS
 LOB (AUDITMSG) STORE AS BASICFILE (TABLESPACE AOS_LOB_TBS COMPRESS HIGH)
   COMPRESS FOR ALL OPERATIONS
)
/

So i found out the reason for this ora error code: ORA-43856.   If you look at the create statement,  I have a BASICFILE instead of SECUREFILE.  With the SECUREFILE it works fine as long as your tablespace is ASSM, otherwise you will receive a message like this as well:

*
ERROR at line 1:
ORA-43853: SECUREFILE lobs cannot be used in non-ASSM tablespace "AOS_LOB_TBS"

Hope this helps.