ORA-14692: STORE AS clause is not allowed for extended character type column

I was trying to import (oracle's legacy imp ) an oracle (12cR1) imp backup where we we set max_string_size=extended in both destination and target database. but while import we faced below issue. 

  IMP-00017: following statement failed with ORACLE error 14692: 

 IMP-00003: ORACLE error 14692 encountered 

ORA-14692: STORE AS clause is not allowed for extended character type column 

ORA-14692: STORE AS clause is not allowed for extended character type column 14692. 00000 - "STORE AS clause is not allowed for extended character type column" *Cause: An attempt was made to use the STORE AS clause to specify storage attributes for an extended character type column. Action: Correct the statement and reenter.

 

 

Alternative Solution :  Then I used data pump (expdp/impdp) and didn't face this issue. so I think, Oracle's legacy exp/imp  doesn't recognise the extended datatype feature How to increase varchar2 column to 32k character size? which is started from oracle 12c onwards.