Dear Tom
I have a table named table1 witch have a clob column named column1 that contains xml data.
for user1 in this database query

select extractvalue(column1,'//xpath') from table1

works fine but after copying this table to another user in the same database i get
ORA-00932: inconsistent datatypes expected - got -
i noticed that

select extractvalue(xmltype(column1),'//xpath') from table1

works for second user but it needs changing developed software that it's not possible any progress is appreciated
First USER1 DDL is

  CREATE TABLE "USER1"."TABLE1" 
   ( "SN_ID" NUMBER, 
 "SN_NOTEID" VARCHAR2(20), 
 "SN_TITLE" VARCHAR2(1000), 
 "SN_OLDNOTEID" NUMBER, 
 "SN_FORMATID" NUMBER, 
 "COLUMN1" CLOB, 
 "SN_FOOTER" VARCHAR2(4000), 
 "SN_GROUP" NUMBER, 
 "SN_CREATEDATE" DATE, 
 "SN_USER" NUMBER, 
 "SN_SECLEVEL" CHAR(1), 
  CONSTRAINT "CHK_SEC_LEVEL_NOTE" CHECK (SN_SECLEVEL in ('L','M','H')) ENABLE, 
  CONSTRAINT "PK_TABLE1_ID" PRIMARY KEY ("SN_ID", "SN_FORMATID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"  ENABLE
   ) SEGMENT CREATION IMMEDIATE 
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 
 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" 
 LOB ("COLUMN1") STORE AS BASICFILE (
  TABLESPACE "USERS" ENABLE STORAGE IN ROW CHUNK 8192 RETENTION 
  NOCACHE LOGGING 
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)) 

and second user DDL is

  CREATE TABLE "USER2"."TABLE1" 
   ( "SN_ID" NUMBER, 
 "SN_NOTEID" VARCHAR2(20), 
 "SN_TITLE" VARCHAR2(1000), 
 "SN_OLDNOTEID" NUMBER, 
 "SN_FORMATID" NUMBER, 
 "COLUMN1" CLOB, 
 "SN_FOOTER" VARCHAR2(4000), 
 "SN_GROUP" NUMBER, 
 "SN_CREATEDATE" DATE, 
 "SN_USER" NUMBER, 
 "SN_SECLEVEL" CHAR(1), 
  CONSTRAINT "CHK_SEC_LEVEL_NOTE" CHECK (SN_SECLEVEL in ('L','M','H')) ENABLE, 
  CONSTRAINT "PK_TABLE1_ID" PRIMARY KEY ("SN_ID", "SN_FORMATID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"  ENABLE
   ) SEGMENT CREATION IMMEDIATE 
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 
 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" 
 LOB ("COLUMN1") STORE AS BASICFILE (
  TABLESPACE "USERS" ENABLE STORAGE IN ROW CHUNK 8192 RETENTION 
  NOCACHE LOGGING 
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT))