How to update models to 1.9 or 1.11 [Solved]

[TheEzeJC]

So currently all my models are in 1.8 format, but in 1.9 and over the models are corrupt.
Is there a way to update the models at once besides remodeling everything?

[HanFox]

What does "corrupt" mean? The only difference between 1.8 and 1.9 is that 1.9 supports left and right handed displays.

1.11+ also requires that all your file/folder names are lowercase.

[TheEzeJC]

What does "corrupt" mean? The only difference between 1.8 and 1.9 is that 1.9 supports left and right handed displays.

1.11+ also requires that all your file/folder names are lowercase.

Like I'm just transferring my old 1.8 models to a 1.9 texture pack. I've made sure the texture is correct, no capitals (looked this up before posting), but still no luck. The model is 3d, but appears larger than normal in hand, ground, wall, and inventory. Would I have to reopen every single model again and re-export, or start from scratch? I made the models before studio was released, so would that be the problem?

[HanFox]

As I said, 1.9 has support for left and right hands. So, yes, you'll need to redefine all the display positions again.

[TheEzeJC]

As I said, 1.9 has support for left and right hands. So, yes, you'll need to redefine all the display positions again.

Ok, so I've upgraded everything to 1.9
During that I created some new models that I enjoy.
I have tried using them in 1.8 by just directly dropping them into the models folder, but no luck. The block model itself looks fine, but when being held it appears smaller/bigger.
I have used Cubik Studio for MacOS. Would that be the problem?