Reproduction steps:
1. Open the Project inside of the "JSmini.zip"
2. Inside the Addressables Assets window -> Build -> Build Player Content

Expected: Addressable Player Content finishes building
Actual: An exception is thrown and Player Content fails to build

Reproduces on: 2018.3.3f1 and 0.5.2
Could not reproduce on 2019.1.0b1, 2019.2.0a2 due to Editor freezing after opening the project and on older package versions due to version change breaking Addressable's configuration assets

Note: Thrown exception
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.AddressableAssets.GenerateLocationListsTask.GetLoadPath (UnityEditor.AddressableAssets.AddressableAssetGroup group, System.String name) (at Library/PackageCache/com.unity.addressables@0.5.2-preview/Editor/Build/BuildPipelineTasks/GenerateLocationListsTask.cs:79)
UnityEditor.AddressableAssets.GenerateLocationListsTask.Run () (at Library/PackageCache/com.unity.addressables@0.5.2-preview/Editor/Build/BuildPipelineTasks/GenerateLocationListsTask.cs:66)
UnityEditor.Build.Pipeline.BuildTasksRunner.Run (System.Collections.Generic.IList`1[T] pipeline, UnityEditor.Build.Pipeline.Interfaces.IBuildContext context) (at Library/PackageCache/com.unity.scriptablebuildpipeline@1.2.1-preview/Editor/Shared/BuildTasksRunner.cs:50)
UnityEditor.GenericMenu:CatchMenu(Object, String[], Int32)