Assets\PostProcessing\Runtime\Components\LeiaDepthOfFieldComponent.cs(5,20): error CS0246: The type or namespace name ‘BuiltinDebugViewsModel’ could not be found (are you missing a using directive or an assembly reference?)
We found the source of the issue. LeiaDOFPostProcessingStack_v0.5.0.unitypackage is dependent on Post Processing Stack version 1. Since the creation of this package, Unity support for PPSv1 has been dropped.
To resolve the error messages:
Delete the Post Processing folder at Assets > PostProcessing
In an upcoming release we will support PPSv2. We do not have a date for that release at this moment.