Does this version work?
BEGIN TRY
  DROP TABLE #adr_test;
END TRY
BEGIN CATCH
-- nothing to drop
END CATCH;

CREATE TABLE #adr_test
(
  style  ...

Your ScriptResults enum is missing.
Why are you doing this in a script task rather than a stored procedure? This logic belongs in the database.

Try this:

Incompetence? Lack of care?
I doubt there's a technical reason.

When I run it on 2017, the numbers are sequential.

What is the point of this code?

And please do not rely on the 'quirky update' unless you...

Double-click the constraint line.

Here is a simple C# function which returns true if a file is locked, false otherwise.
    private bool FileIsLocked(string filename, FileAccess file_access)
   ...

I'm sure that there are good reasons for you choosing to do this the way you have, but I do have a few questions / comments.

• DDL operations (CREATE TABLE...

SQL Prompt can do all of the terminator legwork for you.