Hello, I'm trying to follow a standard reference for opening files but running into a constraint_error at the line when I call Ada.Text_IO.Create(). It says "range check failed". Any help appreciated, here's the code:

WITH Ada.Text_IO;
WITH Ada.Integer_Text_IO;
USE Ada.Text_IO;
USE Ada.Integer_Text_IO;

PROCEDURE FileManip IS

   --Variables
   Start_Int : Integer;
   Stop_Int : Integer;
   Max_Length : Integer;

   --Output File
   MaxName : CONSTANT Positive := 80;
   SUBTYPE NameRange IS Positive RANGE 1..MaxName;

   OutFileName : String(NameRange) := (OTHERS => '#');
   OutNameLength : NameRange;
   OutData : File_Type;

   --Array
   TYPE Chain_Array IS ARRAY(1..500) OF Integer;
   Sum : Integer := 1;
BEGIN

--Inputs
   Ada.Text_IO.Put(Item => "Enter a starting Integer: ");
   Ada.Integer_Text_IO.Get(Item => Start_Int);
   Ada.Text_IO.New_Line;
   Ada.Text_IO.Put(Item => "Enter a stopping Integer: ");
   Ada.Integer_Text_IO.Get(Item => Stop_Int);
   Ada.Text_IO.New_Line;
   Ada.Text_IO.Put(Item => "Enter a Maximum Length to search: ");
   Ada.Integer_Text_IO.Get(Item => Max_Length);
   Ada.Text_IO.New_Line;
   Ada.Text_IO.Put(Item => "Enter a output file name > ");
   Ada.Text_IO.Get_Line(
      Item => OutFileName,
      Last => OutNameLength);
   Ada.Text_IO.Create(
      File => OutData,
      Mode => Ada.Text_IO.Out_File,
      Name => OutFileName(1..OutNameLength));
   Ada.Text_IO.New_Line;