I don't know how to fix this error!

Library\PackageCache\com.unity.textmeshpro@3.0.0-preview.14\Scripts\Editor\TMP_PackageUtilities.cs(453,84): error CS0103: The name ‘VersionControlSettings’ does not exist in the current context

I have the same problem

Try deleting your Library/PackageCache folder, reimport the TMP package, restart your Unity.