General SQL Parser - Parse Oracle PL/SQL

We are using SQLParser to check for syntax errors in Oracle SQL sentences. I saw that the library supports PL/SQL, however, we are having issues parsing the following SQL:

declare
 newSeq number;
begin
  select MAX(id_organization)  + 1 into newSeq from c_organization;
  If newSeq > 0 then
    begin
            execute immediate 'DROP SEQUENCE S_C_ORGANIZATION';
      exception when others then
        null;
    end;
    execute immediate 'CREATE SEQUENCE S_C_ORGANIZATION INCREMENT BY 1 START WITH ' || newSeq ;
  end if;
end

Using their C# library with the following code:

TGSqlParser parser = new TGSqlParser(EDbVendor.dbvoracle);
parser.sqltext = sql;
if (parser.checkSyntax() > 0){
    Console.WriteLine(parser.Errormessage);
}

We get:

end of input(10102) near: (0,0) no_root_node(-1000) near: no root node(0,0) end of input(10102) near: (0,0) no_root_node(-1000) near: no root node(0,0)

Any idea if the library supports this kind of PL/SQL statements? (maybe we are doing something wrong)