Windows 8.1 has trouble with old renpy (6.9.3) games

[Galaxy]

So, I admit it, I'm afraid of change, and I still develop on Ren'Py 6.9.3 before the new scripting language and I don't know how to update my old products.

Something seems to have happened to Windows 8.1 in the past few weeks, because now several customers have told me their products (that run fine on Windows 7, which I know because I use Windows 7 currently), won't run at all. They try to run, then just sit there. I had one customer report that compatibility settings didn't help, but I try not to burden customers with figuring out their own problems.

In the past, with similar problems, I've had customers download the latest version of Ren'Py, stick my product folder in there, and run it from the Launcher. But apparently new Ren'Py doesn't want to run stuff from that far back (a traceback file said it was looking for ATL which of course was not to be found).

So... what can I tell these customers, to get their products running now?
And... what do I do to get my products out of the past and into the future? (I guess the answer to that is learn the latest Ren'Py version, reprogram my old products, and create a patch.)

[SundownKid]

Well you could always give your games to someone who knows the new language and pay them to port it over. It shouldn't be too hard to learn it yourself, though.

[PyTom]

Can you give me the traceback? At the very least, I want to fix the backwards compatibility.

Rebuilding for the newest version should just be opening the project in the new Ren'Py, clicking the recompile option, and then building distributions. There were a lot of changes, but they should all be optional.

[Galaxy]

I got the text of the traceback in an email:

I'm sorry, but an uncaught exception occurred.

After initialization, but before game start.
AttributeError: atl

-- Full Traceback
------------------------------------------------------------

Full traceback:
File "C:\Users\Redacted\Downloads\renpy-6.18.3-sdk\renpy\bootstrap.py", line 289, in bootstrap
renpy.main.main()
File "C:\Users\Redacted\Downloads\renpy-6.18.3-sdk\renpy\main.py",
line 307, in main
renpy.game.script.analyze()
File "C:\Users\Redacted\Downloads\renpy-6.18.3-sdk\renpy\script.py",
line 614, in analyze
i.analyze()
File "C:\Users\Redacted\Downloads\renpy-6.18.3-sdk\renpy\ast.py",
line 1130, in analyze
if self.atl is not None:
AttributeError: atl

Windows-post2008Server-6.2.9200
Ren'Py 6.18.3.761

**That's the entire Traceback!!**