I am getting an error message I can't fix

I changed the editor from 2020.something to 2019.4.8f1 and I got this error I can’t fix: Library\PackageCache\com.unity.2d.common@4.0.0\Runtime\InternalBridge\InternalEngineBridge.cs(36,48): error CS0117: ‘SpriteRendererDataAccessExtensions’ does not contain a definition for ‘SetBatchDeformableBufferAndLocalAABBArray’

I am also getting a lot of “TexturePlatformSettings” errors. Please help me!

So you had a project set up in 2020x. Then downgraded it to 2019.4.8f1? And now you are getting a lots of errors? Sound exactly what Unity warns for when you try to downgrade a project. You really shoudn’t do that in most cases. I don’t know if there is some kind of fix, from what I know there isn’t next to just starting over in 2019.4.8f1 or going back to the original version.

If someone comes across this, I was able to fix this error message by reinstalling all 2d packages in Package manager.

Try Unity Collaborate from Package Manager, upgrade to lower version of Collaborate.

This might work.