[orauser@synora ~]$ $ORACLE_HOME/bin/sqlplus LVIV12 as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Sat Aug 25 18:42:22 2018

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Enter password: 

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> show parameter max_string_

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
max_string_size 		     string	 EXTENDED
SQL> create table test_extended (col1 varchar2(32767));

Table created.

SQL>     
SQL> alter session set "_ORACLE_SCRIPT"=true; 

Session altered.

SQL> create user testuser identified by 1;

User created.

SQL> grant create table to testuser;

Grant succeeded.

SQL> grant create session on testuser;
grant create session on testuser
      *
ERROR at line 1:
ORA-00990: missing or invalid privilege


SQL> grant create session to testuser;

Grant succeeded.

SQL> conn testuser
Enter password: 
Connected.
SQL> show parameter max_string_
ORA-00942: table or view does not exist


SQL> create table test_tbl (a varchar2(32767));
create table test_tbl (a varchar2(32767))
                                  *
ERROR at line 1:
ORA-00910: specified length too long for its datatype

create table test_large (a varchar2(32767 byte))
Error report -
SQL Error: ORA-00910: specified length too long for its datatype