Addressables 2.3.7 causes compile errors for editor assemblies (declared via AssemblyReference) that reference Unity.Addressables.Editor.
The following error is reported for all types that have a using UnityEditor declaration and use the Editor type by name:
error CS0118: 'Editor' is a namespace but is used like a type
Looking at the changes in 2.3.7, the problem appears to be Editor/GUI/AddressableAssetEntryTreeViewState.cs, which declares a namespace of Editor.GUI, which I believe should have been UnityEditor.AddressableAssets.GUI to match the other source files in that location.
I’ve filed the bug report and received a reference number, but it has not been added to the Issue Tracker yet. I will update this thread with a link to the issue when it is available.
This issue should be resolved in versions 2.3.16 and 1.23.1. You can use “Install by name” in the Package Manager window with “com.unity.addressables” and the version you want to use.