You cannot perform DDL through EXECUTE IMMEDIATE, I think.

SQL> begin
  2  execute immediate 'create table bob (a number)';
  3  end;
  4  /

PL/SQL procedure successfully completed.

SQL> select 1 from bob;

no rows selected

SQL> 

Did you follow the very first cookiemonster's advice? Because, this is correct way of debugging dynamic SQL. You would get this result after replacing the parameters with some values:

SQL> CREATE TABLE USER.TABLE_NAME
  2  (FIELD1 NUMBER(10) NOT NULL,
  3  FIELD2 NUMBER(10),
  4  FIELD3 NVARCHAR2(50) NOT NULL,
  5  FIELD4 NUMBER(10,0) DEFAULT (0) NOT NULL,
  6  FIELD5 NUMBER(10,0) NOT NULL,
  7  FIELD6 NCLOB NOT NULL,
  8  FIELD7 DATE NOT NULL,
  9  FIELD8 NUMBER(1) DEFAULT (0) NOT NULL),
 10  CONSTRAINT PK_P1_P2 PRIMARY KEY (FIELD2),
 11  CONSTRAINT CHK_P1_PARAMETER2_PROCESSED CHECK (PROCESSED IN (0,1));
FIELD8 NUMBER(1) DEFAULT (0) NOT NULL),
                                      *
ERROR at line 9:
ORA-00922: missing or invalid option

Now change it to valid static statement, then make the same changes in the dynamic one. Next time, please, process these steps yourself.