ORA-39346: data loss in character set conversion for object COMMENT

Error in impdp
Processing object type SCHEMA_EXPORT/TABLE/COMMENT
ORA-39346: data loss in character set conversion for object COMMENT:"NEW_SCHEMA"."SOME_COLUMN"

What to check:

SELECT column_name, comments 

  FROM USER_COL_COMMENTS 

 WHERE column_name = 'TS_E_LAST_IN_NET_EVENT';

Solution:
Replace the comment, with valid text without "garbage" characters
COMMENT ON COLUMN SOME_TABLE.SOME_COLUMN IS 

'Some Valid Comment Text';