How do I play DVD's on my Mac after changing the region 5 times already?

Have you tried changing the region with or without the DVD being inserted?

I’ve tried it with and without. It either won’t lock or it’ll automatically eject the DVD

Unfortunately there isn’t really anything that you can do. The five changes get stored in the firmware of the DVD player so you need to alter the firmware of the DVD player and that comes with risks. It is risky enough that I wouldn’t even try and provide instructions.

Sometimes a Apple store will will reset it back to zero for you so you could always ask.

If I was you I would just use VLC to playback DVDs since that doesn’t care about region codes.

I have had a similar situation, although I put it back where I wanted it before I hit the maximum number of changes.

Does anyone understand the theory behind limiting the number of times? I can’t figure out a reason unless it has something to do with the firmware itself?

@rooeytoo the theory is that Intellectual property owners want you too buy stuff made in/for your region. Largely this is so you can’t play bootlegged cheap stuff from foreign markets.
They “allow” you to change it a few times assuming you might move to other parts of the planet. But if they “allow” unlimited changes then the whole rotten region code thing loses it’s effectiveness.
[ DRM annoys me as I think I should be able to do whatever I want with a machine or media that I own. ]