Just tried updating to Unity SDK 2.48.180809 and received this error when attempting to call PlayFabClientAPI.Matchmake:
"/Client/Matchmake: Generic/unknown HTTP error"
I rolled back the SDK and the Matchmake call works, so it's not impacting me right now, but I just wanted to give a heads up.
Further details:
The full url it attempts to make the call through is https://C949.playfabapi.com/Client/Matchmake?sdk=UnitySDK-2.48.180809
Http code: 400, Http status: BadRequest
Other Client API calls still seemed to work, for example the Login call worked:
https://C949.playfabapi.com/Client/LoginWithCustomID?sdk=UnitySDK-2.48.180809
This happened on my Windows PC, StandaloneWindows64 build, Unity 2018.1.3f1