Hello.
It looks like the latest Unity PlayFabSdk (190424) is broken - it does not compile when Nintendo Switch is the target platform.
It looks like this file was added in the latest release: https://github.com/PlayFab/UnitySDK/blob/versioned/Source/PlayFabSDK/Shared/External/tpl35/System.Threading/CustomInterlocked.cs .
The code in this file tries to call IsZeroPtr() which is not defined anywhere...